The spot on the fault where the pressure first releases is called the

This movement releases energy and generates seismic waves that can be recorded by specialized instruments used by scientists. The point on a fault at which the first movement or break occurs during an earthquake is called the earthquake's hypocenter

Explanation:

the cold front replaces the warmer air at the ground level changing the wind to be breezy and denser.there is also an immediate drop in the temperature.

i think it's letter a.