Final answer:
The technique used by the therapist where Carol read self-help books is known as bibliotherapy which involves reading specific books as a means of promoting personal growth and addressing psychological issues.
Step-by-step explanation:
The technique used by the therapist, where Carol read self-help books, is known as bibliotherapy. Bibliotherapy is a type of therapy that involves reading specific books as a means of promoting personal growth and addressing psychological issues. In this case, reading self-help books could help Carol gain insight into her own thoughts and behaviors and make positive changes in her life.