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
Which muscle paralysis can cause 'Winging of scapula'? 
Select and explain. 
A. Serratus anterior, B. Supraspinatus, C. Teres minor, D. Deltoid
A: Serratus anterior
Answer: A: Serratus anterior 
Explanation: 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.