Which of the following statements about organic compounds is correct?
- AEach molecule of propan-1-ol has one $\text{-OH}$ group and each molecule of propan-2-ol has two $\text{-OH}$ groups.
- BOctane and decane are in a homologous series with the general formula $\text{C}_n\text{H}_{2n}$.
- CThe ester butyl butanoate has eight carbon atoms in each molecule.
- DThe structure of the functional group in a carboxylic acid is $\text{-C-O-O-H}$.