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
The following is true of brachial plexus: 
Select and explain. 
A. Cervical rib involves lateral cord, B. Musculocutaneous nerve arises from medial cord, C. Radial nerve arises from posterior cord, D. Post fixed plexus is formed by C45678 and T1
C: Radial nerve arises from posterior cord
Answer: C: Radial nerve arises from posterior cord 
Explanation: C - B.D. Chourasia, Vol.l, 4th ed, p. 51,52