This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Upper Extremity, Subject name: Anatomy
[{'content': "Which muscle paralysis can cause 'Winging of scapula'? \nSelect and explain. \nA. Serratus anterior, B. Supraspinatus, C. Teres minor, D. Deltoid", 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. a (Serratus anterior) (Ref. Maheshwari orthopedics 4th/56)LONG THORACIC NERVE# Arises from ventral rami of C5, C6, and C7.# Descends behind the brachial plexus on the lateral surface of the serratus anterior, to which it supplies.# The serratus anterior muscle can be examined by asking patient to push against a wall with both hands. Winging of scapula will be typically noted.', 'role': 'assistant'}]