Given that the application is designed to handle only one process at a time to maintain data consistency, here’s why horizontal scaling won’t increase the processing limit:

Single-Process Constraint:

The application limits to processing one transaction at a time due to its design for consistency, meaning horizontal scaling (adding more workers) does not increase processing speed beyond this limit.

Execution Time:

Since each request takes 200 ms, five requests per second is the maximum processing threshold. Increasing the number of workers does not bypass this single-process limitation.

Explanation of Correct Answer (A):

The scalability remains at five requests per second, as this constraint is intrinsic to the application’s design.

Explanation of Incorrect Options:

Option B suggests a change in execution time, which horizontal scaling does not affect.

Option C assumes doubling the throughput, which isn’t possible due to the single-threaded nature of the application.

Option D suggests horizontal scaling cannot apply, which is incorrect; however, scaling does not increase throughput in this context.

ReferencesFor more on understanding scaling and concurrency in Mule applications, see MuleSoft’s documentation on application performance and scaling limitations​.