Which of the following muscles gets fatigued very early?

The region at the ends of the $A$-band of two adjoining sarcomeres is called

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 biceps and triceps muscles are found in

Which mineral element is essential for muscle contraction?

Describe the important steps in muscle contraction.