Answer:
The correct answer is Z disc
Step-by-step explanation:
The Z disk (or Z line) defines the boundaries of a muscle sarcomere. Two adjacent Z disks along the myofibril mark the boundaries of a single sarcomere. The Z disks are the attachment sites for the thin filaments. Therefore, from each Z disk, thin filaments extend to two neighboring sarcomeres.
They run through the core of each thick filament and anchor it to the Z-line, the end point of a sarcomere. Titin also stabilizes the thick filament, while centering it between the thin filaments.