During muscle contraction:

Select the correct statements regarding the mechanism of muscle contraction.
$A.$ It is initiated by a signal sent by $\text{CNS}$ via a motor neuron,not a sensory neuron.
$B.$ Neurotransmitter generates an action potential in the sarcolemma.
$C.$ Increased $Ca^{++}$ level leads to the binding of calcium with troponin on actin filaments.
$D.$ Masking of the active site of actin prevents contraction; unmasking leads to contraction.
$E.$ Utilising the energy from $\text{ATP}$ hydrolysis to form a cross-bridge.

During muscular contraction,which of the following events occur?
$(a)$ $'H'$ zone disappears
$(b)$ $'A'$ band widens
$(c)$ $'I'$ band reduces in width
$(d)$ Myosin hydrolyzes $ATP$,releasing the $ADP$ and $Pi$
$(e)$ $Z$-lines attached to actins are pulled inwards
Choose the correct answer from the options given below.

Choose the correct properties of muscle fibres.
$I.$ Muscle fibre is lined by the plasma membrane called sarcolemma.
$II.$ Cytoplasm of the muscle fibre is called tonoplasm.
$III.$ Sarcolemma of the muscle fibre encloses the sarcoplasm.
$IV.$ Muscle fibre is a syncytium.
Select the correct option.

$\text{ATP}$ase is located in $:-$

During muscle contraction: