Therapist a Recently Read About an Experimental Technique for Treating

Therapist A recently read about an experimental technique for treating eating disorders.Because she is currently treating a client with an eating disorder,Therapist A tells her client that she is going to modify her treatment and begin using the new therapy.What ethical principle could the therapist be violating?

A) She did not fully inform her client that she was switching techniques.
B) She is using her power to influence the client.
C) The therapist is not qualified to use this experimental technique.
D) The therapist is not using the best technique available.