When the Equation Cl₂ $\to$ Cl^- + ClO₃^- (Basic Solution)is Balanced Using the Smallest Whole-Number

When the equation Cl₂ $\to$ Cl^- + ClO₃^- (basic solution) is balanced using the smallest whole-number coefficients,the coefficient of OH^- is:

A) 1
B) 12
C) 3
D) 4
E) 6