Mountains choose one:
a. have roots of continental crust that extend deeper than the level of crust under plains.
b. that are not volcanoes occur in isolation.
c. remain at the same height over long periods of geologic time.
d. are randomly distributed over the earth’s surface.

Mountains have roots of continental crust that extend deeper than the level of crust under plains.

Option A

Explanation:

It is well studied that the roots of the mountain are about 5.6 factor times deep in comparison to their height of the mountain range. The root usually extends up to the 20 kilo meter range of the bottom below the continental crust.

The topography when created on the earth surfaces was made through the broadening of the crust making it buoyant. The roots extends as the mountain rises more in height with a constant pressure level at the crust base.  So, clearly shows that the mountains have their roots deeper in the plains than the crust.