Butan-2-ol is a:

Correct option is D

The correct answer is (d) secondary alcohol.
 Butan-2-ol is an alcohol with the chemical formula C4H10O. It is classified as a secondary alcohol because the hydroxyl (-OH) group is attached to the second carbon atom of the butane chain.
 In secondary alcohols, the carbon atom holding the hydroxyl group is bonded to two other carbon atoms and one hydrogen atom. For butan-2-ol, this structure is:
CH3-CH(OH)-CH2-CH3
Information Booster:
 Primary Alcohol: The hydroxyl group is attached to a carbon atom that is bonded to only one other carbon atom. Example: Butan-1-ol (CH3-CH2-CH2-CH2OH).
 Tertiary Alcohol: The hydroxyl group is attached to a carbon atom that is bonded to three other carbon atoms. Example: 2-Methylpropan-2-ol (CH3)3COH.
 Ketone: A carbonyl group (C=O) bonded to two other carbon atoms. Example: Butan-2-one (CH3-CO-CH2-CH3).