This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Muscle, Subject name: Physiology
A cross-sectional view of a skeletal muscle fiber through the H-zone would show the presence of: 
Select and explain. 
A. Actin & myosin, B. Titin & myosin, C. Actin & titin, D. Myosin only
D: Myosin only
Answer: D: Myosin only 
Explanation: H-zone is at the center of the sarcomere. Cross-sectional view through the H-zone will show only thick filaments, as ends of the thin filaments stop sho of the center of the sarcomere.