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: Medicine
Pathology in motor neuron disease is at? 
Select and explain. 
A. Anterior horn cells, B. Posterior column tracts, C. Spinothalamic tract, D. Peripheral nervous system
A: Anterior horn cells
Answer: A: Anterior horn cells 
Explanation: None