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
The so-called "pseudo-H zone" in a sarcomere is: 
Select and explain. 
A. M line plus lighter areas on its either side, B. Not seen normally in a sarcomere, C. Seen only in an extremely contracted state of a muscle, D. Disappearance of H band during contraction
A: M line plus lighter areas on its either side
Answer: A: M line plus lighter areas on its either side 
Explanation: At the very center of the sarcomere, there is H-zone (the gap between the ends of the thin filaments). The dark line at the center of the H-zone is called M-line. This dark M-line plus the light areas on either side constitutes the pseudo-H zone.