6. mountains that form when large areas of earth gradually move skyward as a unit are called mountains. a. divergent-boundaary b. fault-block c. uplifted d. rift valley

Salutations!

Mountains that form when large areas of Earth gradually move skyward as a unit are called  mountains.

Mountains that form when large areas of Earth gradually move skyward as a unit are called uplifted mountains. They are called uplifted mountains because the tectonic plates below are shattering.

Thus, your answer is option C.

Hope I helped (:

Iknow what you are working on the correct answer is c