The main source of energy during muscle contraction is

Given below are two statements:
$Statement-I$: Plasma creatinine is produced during catabolism of creatinine phosphate in skeletal muscle contraction.
$Statement-II$: Creatinine phosphate provides a ready source of high-energy phosphate.
In the light of the above two statements, choose the most appropriate answer from the options given below.

The largest muscle in the human body is:

The given figure represents the cross-bridge cycle in skeletal muscle. What does step $B$ in the figure represent?

Endomysium is present in which of the following muscles?

In a skeletal muscle fiber,what is the $H$-zone?