Because rocks in eastern North America are generally "older and colder" than those in the West: all else being equal, an M 7 earthquake that strikes on the east coast of the US would produce shaking that would be felt than a similar quake that occurred in the western US.
A) over about the same area
B) over a smaller area
C) over a greater area

Because rocks in eastern North America are generally "older and colder" than those in the West: all else being equal, an M 7 earthquake that strikes on the east coast of the US would produce shaking that would be felt (C) over a greater area than a similar quake that occurred in the western US.

Explanation:

because the rocks are older they may not have the strength to withstand the vibration of the quake so it can be felt over a greater area.

An earthquake is simply the shaking of the earth surface that is being resulted from a sudden release of energy, in the lithosphere of the  Earth and it then creates a seismic waves.

Earthquakes are generally caused when the rock underground suddenly breaks along a crack.

B

Explanation:

It will produce an effect that would be felt over a smaller area when compared with the effect of same earthquake that occurred in the western US due to the compactness in the structure as result of cold temperature