After Balancing the Following Equation for the Reaction in Acidic $\rarr$

Multiple Choice

After balancing the following equation for the reaction in acidic media,
H⁺ + HSO₃^-(aq) + MnO₄^-(aq) $\rarr$ MnO₂(s) + HSO₄^-(aq) + H₂O what is the sum of ALL the coefficients in the equation? (Remember to include values of 1 in your summation.) Hint: Start by balancing each half-reaction.

A) 7
B) 9
C) 13
D) 15
E) 19