Answer:
B. point on the surface directly above the earthquake
Explanation:
The earthquake involves the propagation of waves through the inner part of the earth due to natural or artificial processes. This majorly leads to the vibration of the earth crust of the affected region as the waves propagates. Thereby, causing sometimes the a violent break up of the surface of the earth from within.
Therefore, the focus of an earthquake is majorly called its epicenter, which is a point on the surface directly above the earthquake itself.