Final answer:
Rational emotive therapy is focused on challenging the client's self-defeating thoughts, which is represented by option (C).
Step-by-step explanation:
Rational emotive therapy (RET), designed by Albert Ellis, is a type of cognitive-behavioral therapy that helps individuals identify and challenge their self-defeating thoughts and beliefs. To answer the student's question, the correct option is (C) Challenge the self-defeating thoughts of the client.
RET operates on the assumption that cognitions, emotions, and behaviors are interconnected and that changing one can change the others. This therapeutic approach involves helping clients recognize irrational beliefs that lead to emotional and behavioral issues, disputing these beliefs, and replacing them with more rational ones, thus assisting in the reduction of psychological distress.