Aepicenter
Bfault line
Cseismic zone
Dfocus
Answer:
D. focus
Read Explanation:
Earthquake
Rocks in the deeper interior of the earth undergo displacement and faults due to plate movements and other causes. Under such situations, severe pressure is exerted on the earth's lithosphere and seismic waves are generated just like waves in a pond spreading in all directions when a heavy object falls into it. These waves create tremors on the earth's surface. These tremors are experienced by us as earthquake.
Apart from plate movements and faulting, earthquakes occur due to other reason as well. These are:
Collapse of roofs of mines
Pressure in reservoirs
Voclanic eruptions
The deep points inside the earth where the earthquake occurs are known as focus and the point vertically above on the earth's surface is known as epicenter.