An ester has the formula $\mathrm{CH}_3\mathrm{CH}_2\mathrm{CH}_2\mathrm{COOCH}_2\mathrm{CH}_2\mathrm{CH}_3$. Which acid and which alcohol combine to form this ester?
- Aacid: butanoic acid; alcohol: butanol
- Bacid: butanoic acid; alcohol: propanol
- Cacid: propanoic acid; alcohol: butanol
- Dacid: propanoic acid; alcohol: propanol