Changing the temperature of an electrochemical cell will affect which two variables?

A: the reactivity of the metal electrode and the concentration of the electrolyte fluid
B:the free energy of the half-reaction and the reaction rate
C: the free energy of the half-reaction and the reactivity of the metal electrode
D:the reaction rate and concentration of the electrolyte fluid

I think both B and C are correct but I suspect B is the answer your instructor wants.