Ans. is 'a' i.e., Axillary nerve NERVE SUPPLY OF MUSCLES OF UPPER LIMBDorsal scapular nerve (C5)Rhomboid minor, rhomboid major, levator scapulae musclesLong thoracic nerve (C5, 6, 7)Serratus anterior muscleSuprascapular nerve (C5, 6)Supraspinatus and infraspinatus musclesNerve to subclavius (C5, 6)SubclaviusLateral pectoral nerve (C5, 6, 7)Pectoralis major muscleMusculocutaneous nerve (C5, 6,7)Coracobrachialis biceps brachii, brachialis muscles, supplies skin along lateral border of forearm when it becomes the lateral cutaneous nerve of forearm.Upper subscapular nerve (C5, 6)Subscapularis muscleThoracodorsal nerve (C6, 7, 8)Latissimus dorsi muscleLower subscapular nerve (C5, 6)Subscapularis and teres major musclesAxillary nerve (C5, 6)Deltoid and teres minor muscles; upper lateral cutaneous nerve of arm supplies skin over lower half of deltoid muscle.Radial nerve (C5, 6, 7, 8; T1)Triceps, anconeus, part of brachialis, extensor carpi radialis longus, via deep radial nerve branch supplies extensor muscles of forearm; supinator, extensor carpi radialis brevis, extensor carpi ulnaris, extensor digitorum, extensor digiti minimi, extensor indicis, abductor pollicis longus, extensor pollicis longus, extensor pollicis brevis; skin, lower lateral cutaneous nerve of arm, posterior cutaneous nerve of arm, and posterior cutaneous nerve of forearm, skin on lateral side of dorsum of hand and dorsal sufrace of lateral three and a half fingers, articular branches to elbow, wrist and hand.Medial pectoral nerve (C8; T1)Pectoralis major and minor musclesMedial cutaneous nerve of arm joined by intercostal brachial nerve from second intercostal nerve (C8; T1, 2)Skin of medial side of armMedial cutaneous nerve of forearm (C8;T1)Skin of medial side of forearmUlnar nerve (C8; T1)Flexor carpi ulnaris and medial half of flexor digitorum profundus, flexor digiti minimi, opponens digiti minimi, abductor digiti minimi, adductor pollicis, third and fourth lumbricals, interossei, palmaris brevis, skin of medial half of dorsum of hand and palm, skin of palmar and dorsal surfaces of medial one and a half fingers.Median nerve (C5, 6, 7, 8; T1)Pronator teres, flexor carpi radialis, palmaris longus, flexor digitorium superficial, abductor pollicis brevis, flexor pollicis brevis, opponens pollicis, first two lumbricals (by way of anterior interosseous branch), flexor pollicis longus, flexor digitorum profundus (lateral half), pronator quadratus, palmar cutaneous branch to lateral half of palm and digital branches to palmar surface of lateral three and a half fingers, articular branches to elbow, wrist, and carpal joints.