Balance the Reaction Below in Acidic Aqueous Solution, Using the Oxidation

Balance the reaction below in acidic aqueous solution, using the oxidation number method. In the balanced equation, what is the coefficient of Fe²⁺? ClO₂^- + Fe²⁺ $\rightarrow$ Cl^- + Fe³⁺

A) 5
B) 4
C) 8
D) 1
E) 7