In flexing the forearm at the elbow, the ________. Naim 20:18 The Muscular System In flexing the forearm at the elbow, the ________. A) biceps brachii acts as antagonist B) triceps brachii acts as antagonist C) brachioradialis acts as antagonist D) coracobrachialis acts as antagonist Answer: B Learn More : Share this Share on FacebookTweet on TwitterPlus on Google+