Studies of Wives' Evaluations of the Post‑heart Attack Physical Abilities

Studies of wives' evaluations of the post‑heart attack physical abilities of their husbands indicate that wives develop more accurate evaluations by

A) having heart attack patients tell them about their capabilities.
B) simply observing the physical activity of patients.
C) personally participating in patients' activities.
D) having physicians tell them what their husbands were capable of doing.