When does blood pressure increase during the respiratory cycle?

Breathing involves ...$A$... during which atmospheric air is drawn in and ...$B$... by which the alveolar air is released out.
Choose the correct option for $A$ and $B$ to complete the given $NCERT$ statement.

In the expiration condition,the diaphragm becomes

When do the expiratory muscles contract?

Sugar is converted into starch when the $pH$ of guard cells increases,which is associated with:

Select the correct process that occurs during inspiration (inhalation):
$(a)$ Contraction of the diaphragm
$(b)$ Contraction of external intercostal muscles
$(c)$ Decrease in pulmonary volume
$(d)$ Increase in intra-pulmonary pressure