According to the sliding filament theory, what is the physical change that takes place during contraction?
a. The Z lines are sliding toward the H zone.
b. The thin filaments are sliding toward the center of the sarcomere alongside the thick filaments.
c. The thick filaments are sliding toward the center of the sarcomere alongside the thin filaments.
d. The thick and thin filaments are sliding toward the center of the sarcomere together.