<s>[INST] context: Erb-Duchenne PalsyUpper lesions of the brachial plexus are injuries resulting from excessive displacement of the head to the opposite side and depression of the shoulder on the same side. This causes excessive traction or even tearing of C5 and C6 roots of the plexus. It occurs in infants during a difficult delivery or in adults after a blow to or fall on the shoulder.The suprascapular nerve, the nerve to the subclavius, and the musculocutaneous and axillary nerves all possess nerve fibers derived from C5 and C6 roots and will therefore be functionless.The following muscles will consequently be paralyzed: the supraspinatus (abductor of the shoulder) and infraspinatus (lateral rotator of the shoulder); the subclavius (depresses the clavicle); the biceps brachii (supinator of the forearm, flexor of the elbow, weak flexor of the shoulder) and the greater pa of the brachialis (flexor of the elbow) and the coracobrachialis (flexes the shoulder); and the deltoid (abductor of the shoulder) and the teres minor (lateral rotator of the shoulder).Thus, the limb will hang limply by the side, medially rotated by the unopposed sternocostal pa of the pectoralis major; the forearm will be pronated because of loss of the action of the biceps.The position of the upper limb in this condition has been likened to that of a poer or waiter hinting for a tip. In addition, there will be a loss of sensation down the lateral side of the arm.TreatmentThe three most common treatments from Erb's Palsy are: Nerve transfers (usually from the opposite leg), sub scapularis releases and latissimus dorsi tendon transfers. [/INST] question: Nerve roots involved in Erb's palsy: | options: A: C5, C6 B: C6, C7 C: C7,C8,T1 D: C5,C6,C7,C8,T1 | answer: A </s>