Starting from iodoethane, which reaction sequence would give propanoic acid as the main product in good yield?
- Aadd $\text{NaOH(aq)}$, isolate the organic product, add acidified $\text{K}_2\text{Cr}_2\text{O}_7$ and boil under reflux
- Badd $\text{NaOH(aq)}$, isolate the organic product, add $\text{H}_2\text{SO}_4\text{(aq)}$ and boil under reflux
- Cheat with $\text{HCN}$ in ethanol, isolate the organic product, add $\text{H}_2\text{SO}_4\text{(aq)}$ and boil under reflux
- Dheat with $\text{KCN}$ in ethanol, isolate the organic product, add $\text{H}_2\text{SO}_4\text{(aq)}$ and boil under reflux