How Does the Exhaust Method Control Smoke

How does the exhaust method control smoke?

A) Uses mechanical fans and ventilation to create a pressure difference across a barrier.
B) Uses high velocity air aimed at the area of origin to keep smoke from migrating into unaffected areas.
C) Uses barriers with sufficient fire endurance to provide protection against the spread of fire and smoke.
D) Uses mechanical ventilation and the properties of smoke to collect smoke at the highest point in a large space.