This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Anatomy
Thickest nerve in the body is - 
Select and explain. 
A. Trigeminal nerve, B. Radial nerve, C. Femoral nerve, D. Sciatic nerve
D: Sciatic nerve
Answer: D: Sciatic nerve 
Explanation: The sciatic nerve is the thickest and largest nerve in the body.
The sciatic nerve is the largest branch of sacral plexus and is the largest nerve in the body. It is formed at the lower margin of piriformis by union of its tibial and common peroneal parts.
The main trunk has following branches :


From tibial componentSemitendinosus, semimembranosus, long head of biceps femoris, and ischeal part of adductor magnus.
Common peroneal componentShort head of biceps femoris.


Thus main trunk of Sciatic nerve supplies hamstrings (semitendinosus, semimembranosus, biceps femoris) and ischeal part of adductor magnus.
In the upper angle of popliteal fossa, sciatic nerve divides into tibial nerve and common peroneal nerve.