Which reaction would form propanoic acid as one of the products?
- Aheating $(\text{CH}_3)_2\text{C}=\text{CHCH}_2\text{CH}_3$ with concentrated, acidified $\text{KMnO}_4$
- Bheating $\text{CH}_3\text{CH}_2\text{CO}_2\text{CH}_2\text{CH}_2\text{CH}_3$ with $\text{NaOH(aq)}$
- Cheating $\text{CH}_3\text{CH}_2\text{OH}$ with acidified $\text{K}_2\text{Cr}_2\text{O}_7$ under reflux
- Dreacting $\text{CH}_3\text{CHO}$ with $\text{HCN}$ then heating the organic product with $\text{H}_2\text{SO}_4\text{(aq)}$