This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General physiology, Subject name: Physiology
Sarcomere extends between 
Select and explain. 
A. A band & I band, B. Two Z lines, C. Two I bands, D. None
B: Two Z lines
Answer: B: Two Z lines 
Explanation: The area between two adjacent Z lines is called a sarcomere. The thick filaments are lined up to form the A bands, whereas the array of thin filaments extends out of the A band and into the less dense staining I bands.(REF.GANONG'S REVIEW OF MEDICAL PHYSIOLOGY -23rd EDITION. Page No-95.)