The process of breathing involves two stages:

The correct option is A Inhalation and Exhalation
$\bullet$ Breathing involves two stages -- inspiration/inhalation and expiration/exhalation. Inspiration is a stage where atmospheric air is drawn in and expiration is the stage where the air inside the lungs is released out. The movement of air into and out of the lungs is carried out by creating a pressure gradient between the lungs and the atmosphere.

$\bullet$ Ventilation is used in terms of the circulation of air inside a room.

$\bullet$ Egestion is the process of discharging the waste material from the body.