For the Reaction I^-(aq) + OCl^-(aq) $\rarr$ IO^-(aq) + Cl^-(aq) in Basic Solution, It Was Found That

For the reaction I^-(aq) + OCl^-(aq) $\rarr$ IO^-(aq) + Cl^-(aq) in basic solution, it was found that

A) This reaction is first order overall.
B) This reaction is third order overall.
C) This reaction is second order overall.
D) This reaction is first order in [OH^-] concentration.
E) The rate law is incorrect as OH^- is neither a reactant nor a product.