Masters and Johnson Developed Their Approach to Therapy Based on What

Masters and Johnson developed their approach to therapy based on what observation regarding couples seeking therapy?

A) Couples seeking therapy were usually very angry at each other.
B) Couples seeking therapy were usually both suffering from low desire.
C) Couples seeking therapy usually avoided all touching so as to avoid dealing with the sexual problem they were having.
D) Couples seeking therapy usually had a problem linked to physiology.