The H-zone in the skeletal muscle fibre is due to:
1. | The central gap between myosin filaments in the A-band. |
2. | The central gap between actin filaments extends through myosin filaments in the A-band. |
3. | Extension of myosin filaments in the central portion of the A-band |
4. | The absence of myofibrils in the central portion of the A-band. |