Is a Fuel- Cell Vehicle Properly Described as a "Heat

Is a fuel- cell vehicle properly described as a "heat engine"?

A) No, because it converts electric energy directly into chemical energy.
B) No, because it converts chemical energy directly to electric energy.
C) Yes, because it uses thermal energy to produce electricity.
D) Yes, because it uses chemical energy to create electric energy.
E) Yes, because it uses thermal energy to do work.