What is true about all plutonsthey form above earth surfacethey form below earth surfacethey cut across other rock layersthey form near earth surface

they form below earth's surface

Explanation:

A plutonic is a body of the igneous rocks that are formed by the crystallization of the magma and the slowly cooling below the earth surface, a pluton is in tabular rocks that are formed by the single magmatic event, more smaller bodies are described as the batholiths and thus have been used interchangeably. And they tend to be different from the volcanic rocks as they are formed above the ground surfaces.

I'm pretty sure it's c. extremely gradual but not 100% sure though.