Correct Option: B

Ventilation is a room air distribution strategy where conditioned outdoor air is supplied at floor level and extracted above the occupied zone, usually at ceiling height. A typical displacement ventilation system, such as one in an office space, supplies conditioned cool air from an air handling unit (AHU) through a low induction diffuser. The cool air spreads through the floor of the space and then rises as the air warms due to heat exchange with heat sources in the space (e.g., occupants, computers, lights). The warmer air has a lower density than the cool air, and thus creates upward convective flows known as thermal plumes. The warm air then exits the zone at the ceiling height of the room.