Question

a. triceps brachii
b. deltoid
c. biceps brachii
d. quadriceps

Explanation:

The triceps brachii is in the upper - arm, the deltoid is on the shoulder, and the biceps brachii is also in the upper - arm. The quadriceps are located on the front of the thigh, which is the muscle group shown in the image.

Answer:

D. Quadriceps