When compared to hypnosis, Sigmund Freud found __________ to be a more gradual method of breaking through the walls of defense that block a client's insight into unconscious processes.

A) confirmation bias
B) modeling
C) free association
D) aversive conditioning

Free association involves freely speaking whatever comes to mind without censorship or judgment, which allows the client to access and explore unconscious thoughts and emotions in a gradual and non-threatening way. Hypnosis may also be effective in accessing the unconscious, but can be more abrupt and potentially overwhelming for some clients. While modeling and aversive conditioning are techniques used in therapy, they are not directly related to breaking through defenses to access the unconscious. Confirmation bias refers to the tendency to interpret information in a way that confirms one's preexisting beliefs or expectations and is not a therapeutic technique.