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
In poliomyelitis which part of spinal canal is involved: 
Select and explain. 
A. Anterior horn, B. Lateral horn, C. Posterior horn, D. Medial horn
A: Anterior horn
Answer: A: Anterior horn 
Explanation: None