What Do Systematic Desensitization and Implosion Therapy Have in Common

What do systematic desensitization and implosion therapy have in common?

A) They are both forms of group therapy that involve multiple clients.
B) They are both forms of active listening used by humanistic therapists.
C) They are both forms of interpretation used by psychodynamic therapists.
D) They are both exposure techniques used by behavioral therapists.