A Factor That Decreases the Activation Energy for a Reaction

A factor that decreases the activation energy for a reaction:
I. decreases the rate constant
II. increases the rate constant
III. has no effect on the rate constant
IV. makes the product yield increase
V. might be a catalyst

A) I and IV
B) II and IV
C) I, IV, and V
D) IV and III
E) II and V