Which of the following is a pair of functional isomers?

Options

A. `CH_(3)COCH_(3)CH_(3) CHO`
B. `C_(2)H_(5)CO_(2)H,CH_(3)CO_(2)CH_(3)`
C. `C_(2)H_(5)CO_(2)H,HO_(2)CC_(2)H_(5)`
D. `CH_(3)CO_(2)H,CH_(3)CHO`

Answer

B

Explanation

Functional isomerism can be seen in compounds having same molecular formula but different functional groups. Carboxylic acid and ester show functional isomerism ie., `C_(2)H_(5)COOH` and `CH_(3)COOCH_(3)`