Answer:
Triceps brachii.
Explanation:
Tricep brachi muscle is present at the back of the upper limb. This muscle extend distally to the teres minor and lies posteriorly to the teres major.
The most important function of tricep brachii muscle is the extansion of forearm at the elbow joint, results in the arm straightening. This muscle works antagonist to the bicep muscle.
Thus, the answer is tricep brachii muscle.
