Which Statement Comes Closest to Describing the Isostatic Compensation Under

Multiple Choice

Which statement comes closest to describing the isostatic compensation under convergent continental mountain belts?

A) The extra elevation of mountains, like that of icebergs above the sea, is held up by the weight of the denser material that their lower portions displace.
B) The extra elevation of mountains is maintained almost entirely by rising mantle plumes.
C) The extra elevation of mountains is accounted for by the missing mass from adjacent eroded valleys and flanking lowland areas.
D) The extra elevation of mountains is maintained by active elastic compression supplied by earthquake cycles and crustal convergence.