Which muscles undergo contraction during normal expiration?

In rabbits,inspiration occurs by the contraction of:

$A$ healthy human breathes $........$ times per minute.

Hiccups are caused by the activity of which of the following?

An $A$ in the pulmonary volume $B$ the intra-pulmonary pressure to less than the atmospheric pressure which forces the air from $C$ to move into the lungs,i.e.,$D$. Choose the correct options for the blanks $A, B, C$ and $D$ to complete the above statement with reference to $NCERT$ textbook.

Arrange the given steps of expiration in the sequence of events occurring first:
$I.$ Relaxation of the diaphragm and sternum
$II.$ Reduction of the pulmonary volume
$III.$ Expulsion of air from the lungs
$IV.$ Increase in intra-pulmonary pressure
Choose the correct option.