Where are $ATPase$ enzymes located in a muscle fiber?

Arrange the given steps of muscle contraction in the series of events from first to last.
$I.$ Myosin head binds to the exposed active site on actin to form a cross bridge.
$II.$ The $Z$-line attached to these actin are also pulled inwards,thereby causing shortening of sarcomere,also called contraction.
$III.$ This pulls the attached actin filaments towards the centre of $A$-band.
The correct option is:

Which of the following statements is correct regarding muscle contraction?

$I-$bands of myofibrils are bisected by

The muscular contraction in which the tension remains the same and the mechanical work is also done is called

Which type of muscle is multinucleated during its functional state?