This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General anatomy, Subject name: Anatomy
H zone contains 
Select and explain. 
A. Only myosin, B. Actin and myosin, C. Alfa actinin, D. None
A: Only myosin
Answer: A: Only myosin 
Explanation: H zone contains Only myosin M line passes from centre of H zone Ref:Guyton and Hall textbook of medical physiology 12th century edition,page number:86,87