The Mechanism for the Reaction 2 H₂O₂(aq) $\rightarrow$ 2 H₂O(l) + O₂(g) in the Presence of I^-(aq) Is

The mechanism for the reaction 2 H₂O₂(aq) $\rightarrow$ 2 H₂O(l) + O₂(g) in the presence of I^-(aq) is proposed to be:
Step 1: H₂O₂(aq) + I ^- (aq) $\rightarrow$ H₂O(l) +OI ^- (aq) (slow)
Step 2: H₂O₂ (aq) + OI ^- (aq) $\rightarrow$ H₂O(l) + O₂(g) +I ^- (aq) (fast) What is the molecularity of the rate-determining step?

A) zeromolecular
B) unimolecular
C) bimolecular
D) termolecular
E) More information is needed.