Figure 9- 1 Skeletal Muscle Fiber

Figure 9- 1 Skeletal Muscle Fiber
Use Figure 9- 1 to answer the following questions:
-Physical evidence that supports the sliding filament theory of muscle contraction includes

A) the I band + H band distance is constant during contraction.
B) increased width of the I band during contraction.
C) decreased width of the A band during contraction.
D) constant distance between Z lines during contraction.
E) decreased width of the H band during contraction.