Question

purpose in rhetorical context refers to: a the external motivation of a reader or writer b the issue the composer is writing about c what a reader or writer is trying to accomplish

Explanation:

In rhetorical context, purpose refers to what a reader or writer is trying to accomplish. It is the goal or aim behind the communication. The external motivation is not the definition of purpose, and the issue the composer is writing about is more related to the subject - matter rather than the purpose.

Answer:

C. What a reader or writer is trying to accomplish