Final answer:
Gneiss, a larger-grained rock, generally exhibits a higher grade of metamorphism.
Step-by-step explanation:
The type of rock that generally exhibits a higher grade of metamorphism is gneiss.
Gneiss is a high-grade, foliated metamorphic rock that forms from the metamorphism of schists or granites. It differs from lower grade foliated metamorphics, such as slate, phyllite, and schist, by having alternating bands or stripes of light and dark minerals. The intense metamorphism of gneiss causes minerals to self-segregate into discrete zones, resulting in its distinctive texture.
In contrast, smaller-grained rocks do not necessarily exhibit a higher grade of metamorphism. The grade of metamorphism is not related to grain size.
Therefore, the correct answer is a) Larger-grained rock.