C2H4 is reduced by H2 in the presence of a solid platinum catalyst, as represented by the equation above. Factors that could affect the rate of the reaction include which of the following
I. Changes in the partial pressure of H2
II. Changes in the particles size of the platinum catalyst
III. Changes in the temperature of the reaction system
A. III only
B. I and II
C. I and III
D. II and III
E. I, II and III