The Oxidation of Cr³⁺ to CrO₄^2- Can Be Accomplished Using

The oxidation of Cr³⁺ to CrO₄^2- can be accomplished using Ce⁴⁺ in a buffered solution. The following data were obtained:
-Determine the order in the rate law of the species Ce⁴⁺.

A) 1
B) -2
C) 3
D) -1
E) 2