Most of the heat for contact metamorphism is supplied by a. radioactive elements b. temperatures deep within earth c. frictional heating along a fault d. a nearby mass of magma

The correct response is Option D. A nearby mass of magma

Explanation:

In geology metamorphism refers to the changes in composition or assemblage that happen when rocks are subjected to new conditions, like new temperatures or pressures. This can create a change in texture or density or composition from what was evident in the rock deposit previously. One kind of metamorphism is called contact metamorphism which results when a rock that is in its solid state, for example, comes into contact with hotter, more liquid magma in close proximity. This causes changes to the original rock as it is heated by the contact.