Answer:
D. May be any of the three rock types.
Step-by-step explanation:
Protoliths mainly fall into two classes: sedimentary rocks, formed from sediment, and igneous rocks, formed from magma. Additionally, protoliths can also be metamorphic rocks. Different protoliths will form different metamorphic rocks under the same conditions of temperature and pressure. The same protolith will form different metamorphic rocks under different conditions of temperature and pressure. Therefore, because protoliths can be sedimentary, igneous, or metamorphic, the answer is D.
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