This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Upper limb, Subject name: Anatomy
[{'content': 'True about pectoralis major muscle \nSelect and explain. \nA. Abductor & Internal rotator of shoulder, B. Blood supply by perforating branch of internal thoracic aery, C. Blood supply by thoraco acromial aery, D. Nerve supply by intercostal aery', 'role': 'user'}, {'content': 'Answer: C \nExplanation: PECTORALIS MAJOR:-Origin: Small clavicular head- medial half of anterior aspect of clavicle.Sternocostal head- lateral half of sternum upto 6th cailage., and medial pas of 2nd to 6th costal cailages.Inseion:-U shaped inseion into lateral lip of bicipital groove.Nerve supply:-Lateral pectoral( C5-C7)Medial pectoral (C6-C8, T1)Action:-Clavicular head- flexes arm Sternocostal head-adducts and medially rotates armOnly muscle of upper limb which is supplied by all 5 spinal segments that form brachial plexus.Blood supply:- pectoral branch of thoracoacromial aery{Reference: Vishram Singh, pg no.40}', 'role': 'assistant'}]