You Have Two Types of Cells That Both Produce a Particular

You have two types of cells that both produce a particular protein. You notice that when you heat up the cells, the first type of cell's protein loses function while the second type of cell's protein retains function. How is this possible?

A) The protein of the second type of cell has a completely different primary structure from the protein of the first type of cell.
B) The second type of cell expresses a chaperone protein that the first type does not.
C) The first cell has weaker mRNA.
D) None of the other answer options is correct.