For this question, use changes in oxidation number to balance a chemical equation. The reaction below takes place when $\text{MnO}_2$ is heated with dilute $\text{H}_2\text{SO}_4$. $a\ \text{MnO}_2 + b\ \text{H}^+ \rightarrow c\ \text{Mn}^{2+} + d\ \text{MnO}_4^- + e\ \text{H}_2\text{O}$ What is the value of the ratio $c:d$ in the balanced equation?
- A$1:1$
- B$1:2$
- C$2:3$
- D$3:2$