The choices can be found elsewhere and as follows:
A.) Rotate the arm at the shoulder with the back straight
B.) Bend the arm at the elbow with the back straight
C.) Rotate the elbow and arch the back
D.) Bend the elbow and move the upper arm forward
I believe the correct answer is option B. Bending the arm at the elbow with the back straight is an example of proper movement from biceps curl. Hope this answers the question.