The Concentration of Iron(II) Ions in Water Can Be Determined $\rightarrow$

The concentration of iron(II) ions in water can be determined by titration with potassium permanganate in acid solution as shown by the incomplete unbalanced reaction equation below. Identify the stoichiometric coefficient of the iron(II) ion in the balanced reaction equation.
Fe²⁺(aq) + MnO₄^- $\rightarrow$ Fe³⁺(aq) + Mn²⁺(aq)

A) 1
B) 2
C) 3
D) 4
E) 5