A protolith
A) is always metamorphic rock.
B) is always igneous rock.
C) is always sedimentary rock.
D) may belong to any of the three primary rock types.

Question

Quizplus · Accepted Answer

A protolith is the original rock from which a metamorphic rock is formed. This original rock can be any of the three primary types of rock: sedimentary, igneous, or metamorphic. Therefore, the best choice is D, which states that a protolith may belong to any of the three primary rock types.

A Protolith