During muscle contraction,which of the following events occurs?

Muscles are red because of the presence of

$A$ bundle of muscle fibre is called

Which of the following muscles are not under the voluntary control of the nervous system?

Given below are two statements $:-$
Statement-$I$ :- Each organised skeletal muscle in human body is made of a number of fascicles,held together by a common connective tissue layer called fascia.
Statement-$II$ :- The portion of the myofibril between two successive '$Z$' lines is considered as the functional unit of muscle contraction,known as a sarcomere.
In the light of the above statements,choose the correct answer from the options given below $:-$

Which muscle band remains unchanged during the contraction and relaxation of the skeletal muscle?