Answer:
If an agonist muscle produces a flexion, the primary action of the antagonist muscle will be extension.
Step-by-step explanation:
Muscles are the organs of the musculoskeletal system that, through their contraction and relaxation, allow body movements.
Due to the location of each muscle in relation to the bone and joint, they can perform diverse movements, there being the so-called agonist and antagonist muscles for each movement.
If an agonist muscle makes a movement, the antagonist muscle or muscles will make the opposite movement, so the extension corresponds to the antagonistic action of the flexion.
The other options are not correct because:
B y D. Abduction and adduction are antagonistic movements, not related to flexion.
C. The antagonistic movement of pronation is supination.