Answer: A band.
- A I band
- B H zone
- C A band
- D Z line
Correct answer: C. A band
Explanation: The A band is the dark, anisotropic region where thick (myosin) filaments lie, overlapping thin filaments at its edges.

A sarcomere (Z line to Z line): during contraction the I band and H zone shorten as thin filaments slide over thick, while the A band stays the same length. Image: SlothMcCarty, CC BY-SA 3.0, via Wikimedia Commons.
Concept context
Types of movement, muscle contraction, skeletal system, joints, and disorders. Important for Class 11 and NEET.