In a patient with erb's palsy, paralysis of which of the following muscles results in medial rotation of the arm?

In a patient with Erb's palsy there is involvement of C5, 6 nerve root. In this condition, the arm is held in adduction and internal rotation at the shoulder, extension at the elbow, pronation of the forearm and flexion at the wrist. Paralysis of the teres minor and infraspinatus result in medial rotation of the arm. Paralysis of Biceps brachii, brachialis and brachioradialis result in extended forearm. Paralysis of Supraspinatus and deltoid result in adducted arm.