Correctly Infer a Researcher's Basic Motivation in This Example: an Art

Correctly infer a researcher's basic motivation in this example: An art therapist wants to understand why a client dropped out of treatment prematurely.

A) To prove that art therapy is effective
B) To predict how well clients will respond to art therapy
C) To understand client needs in order to improve treatment
D) To accurately identify the client's diagnosis from a sample of his artwork