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
Ulnar collateral nerve is 
Select and explain. 
A. Branch of ulnar nerve, B. Branch of radial nerve supplying medial head of triceps, C. Branch of radial nerve supplying long head of biceps, D. Branch of radial nerve supplying lateral head of triceps
B: Branch of radial nerve supplying medial head of triceps
Answer: B: Branch of radial nerve supplying medial head of triceps 
Explanation: In the arm, the radial nerve is posterior to the brachial aery. Here it gives muscular branches to long and medial heads of triceps brachii. The branch for medial head lies very close to the ulnar nerve and hence is called the ulnar collateral nerve. ReferenceClinicall Anatomy for students, a problem-solving approach, Neeta v Kulkarni, 2nd edition, page no.179