Balance the Chemical Equation for the Following Redox Reaction Under $\to$

Balance the chemical equation for the following redox reaction under acidic aqueous conditions with the smallest whole-number coefficients possible using the half-reaction method.What is the coefficient of Cl^-? Cl₂(g) + S₂O₃^2-(aq) $\to$ Cl^-(aq) + SO₄^2-(aq)

A) 2
B) 4
C) 5
D) 8
E) 10