Final answer:
The correct answer is A) No change.
Step-by-step explanation:
The correct answer is A) No change. The phrase 'Author's Viewpoint and Purpose' is grammatically correct and coherent as it describes the dual elements of interpretation and intent carried by the author of a text. The singular possessive form 'Author's' accurately represents that the viewpoint and purpose belong to a single author. Therefore, the given sentence does not require any changes in terms of subject-verb agreement or noun form.