66 As a part of training, suitable audio-visual materials should be presented for the trainee instructors to review . The main purpose of screening such videos-films shall be to

A. make the teaching process easier with minimum effort and time.
B. make the trainees answer a set of suitable questions after viewing the material.
C. spent a part of the class time to avoid fatigue and concentration losses.
D. divert attention of the trainees from the subject,if found lengthy.