Answer: option A, an alcohol
Explanation: since alcohol has general formula R-OH.
We call them as hydroxy derivatives of alkanes or derivatives of water.
Since hydrogen atom of water is replaced by Alkyl group.
Examples: CH3OH(methanol), CH3CH2OH(ethanol)
And aldehyde (RCHO) , amide (RCONH2)& amine (RNH2) won't have OH group. Hence A is correct answer