This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: C.N.S., Subject name: Medicine
A 48-year-old man complains of muscle weakness in his right hand (dominant hand). On examination, the hand muscles are smaller than on the left, and the reflexes are decreased out of proportion to weakness.For the above patient with muscle weakness, select the most likely anatomic site for the disorder 
Select and explain. 
A. anterior horn cell, B. peripheral nerve, C. neuromuscular junction, D. muscle
B: peripheral nerve
Answer: B: peripheral nerve 
Explanation: Peripheral nerve lesions result in reflex loss greater than the degree of weakness. Reflex loss is variable in anterior horn cell disease and decreased proportionately in muscle disease. In neuromuscular junction disorders, reflexes are characteristically normal.