D.

Expose an HTTP callback API in Mule and register it with the external system

Explanation:
To get response data from the external API after it completes processing, the developer should expose an HTTP callback API in Mule and register it with the external system. This way, the external API can invoke the callback API with the response data when it is ready, instead of making the Mule application wait for a long time or poll for a response repeatedly. 

References:
https://docs.mulesoft.com/mule-runtime/4.3/http-listener-ref#callback

C.

Set an appropriate keystore and truststore configuration for the listener

To enable mTLS authentication for HTTP Listener, the developer needs to set an appropriate keystore and truststore configuration for the listener. The keystore contains the certificate and private key of the Mule application that are used to prove its identity to clients. The truststore contains the certificates of trusted clients that are allowed to access the Mule application.

References:
https://docs.mulesoft.com/mule-runtime/4.3/tls-configuration#mutual-authentication

C.

Create a Mule Plugin project
Create a common-global-error-handler flow inside the plugin project.
Use this plugin as a dependency in all Mule applications

Explanation:
To configure a common-global-handler flow that can be reused across all of the organization’s deployed applications, the developer should create a Mule Plugin project, create a common-global-error-handler flow inside the plugin project, and use this plugin as a dependency in all Mule applications. This way, the developer can import the common-global-error-handler flow in any application that needs it and avoid duplicating the error handling logic. 

References:
https://docs.mulesoft.com/mule-runtime/4.3/error-handling#global-error-handler

A.

Store the contents of the file on separate storage, and store the key and location of the file Object using Object Store v2

To temporarily persist large files over 10MB between flow executions, and routinely query whether the file data exists on separate executions, the developer should store the contents of the file on separate storage, and store the key and location of the file object using Object Store v2. This way, the developer can avoid storing large files in memory or exceeding the size limit of Object Store v2 (10MB per object). The developer can also use Object Store v2 operations to query, retrieve, or delete the file object by its key.

References:
https://docs.mulesoft.com/object-store/osv2-faq#can-i-store-files-in-object-store-v2

D.

Wrap all Anypoint MQ Publish operations within a With CorrelationID scope from the Tracing module, setting the correlation ID to the order ID

Explanation:
To propagate the order ID as the correlation ID across each message using Anypoint MQ, the developer should wrap all Anypoint MQ Publish operations within a With CorrelationID scope from the Tracing module, setting the correlation ID to the order ID. The With CorrelationID scope allows setting a custom correlation ID for any event that occurs within it. The Tracing module also enables distributed tracing across different Mule applications and services using Anypoint Monitoring.

References:
https://docs.mulesoft.com/tracing-module/1.0/tracing-module-reference#with-correlation-id-scope
https://docs.mulesoft.com/tracing-module/1.0/tracing-module-concepts

A.

Object Store v2 REST API

Explanation
To remove values from Mule application A’s Object Store v2, Mule application B can use Object Store v2 REST API. This API allows performing operations on Object Store v2 resources using HTTP methods, such as GET, POST, PUT, and DELETE. Mule application B can use the DELETE method to remove values from Mule application A’s Object Store v2 by specifying the object store ID and the key of the value to delete.

References: https://docs.mulesoft.com/object-store/osv2-apis

C.

An encryption algorithm

Explanation
A cipher suite is a set of cryptographic algorithms that are used to secure the communication between a client and a server. A cipher suite consists of four components: a key exchange algorithm, an authentication algorithm, an encryption algorithm, and a message authentication code (MAC) algorithm. During the cipher suite exchange, the client and the server agree on which encryption algorithm to use for encrypting and decrypting the data.

References: https://docs.mulesoft.com/mule-runtime/4.3/tls-configuration#cipher-suites

C.

Scatter-Gather as central Saga orchestrator for all API request with compensating actions for failing routes

Explanation:
To invoke multiple HTTP APIs in parallel and roll back failed requests in sequence, the developer should use a Scatter-Gather router as a central Saga orchestrator for all API requests with compensating actions for failing routes. A Scatter-Gather router executes multiple routes concurrently and aggregates the results. A Saga orchestrator coordinates a series of actions across different services and handles failures by executing compensating actions. Therefore, using a Scatter-Gather router as a Saga orchestrator allows invoking multiple HTTP APIs in parallel and rolling back any failed requests in sequence. 

References:
https://docs.mulesoft.com/mule-runtime/4.3/scatter-gather-concept
https://docs.mulesoft.com/mule-runtime/4.3/saga