About the energy level diagram given below, which of the following statement or statements is or are correct?

I. The reaction is of two steps and R is an intermediate.
II. The reaction is exothermic and step 2 is rate determining.
III. Q is an intermediate and R is the transition state for the reaction M to Q.
IV. P is the transition state for the reaction Q to N.

A

III and IV

B

I, III and IV

C

I, II and IV

D

III only