Which of the Following Situations Involves a Heterogeneous Catalysis

Which of the following situations involves a heterogeneous catalysis?

A) The catalyst is present in a different phase of matter than are the reactants and products.
B) The catalyst is in two different phases of matter.
C) The reactants and products are different phases of matter in a catalyzed reaction.
D) The catalyst,reactants,and products are all different phases of matter.
E) The catalyst changes phases during the reaction.