If rocks are pushed deep into the earths mantle they wil a) become minerals b) become molten rock c) change into gases or d)become metamorphic rock

They would become molten rocks, this answer makes the most since.

The answer to this will be from your lab notes/procedure. it would be best to ask another student who participated in the lab as we do not know what was done, what enzyme or if the temperature is celsius or fahrenheit. if i were to guess though i'd say the rate stopped due to enzyme denturing at high temperature