The explosive nitroglycerin is a

Correct answer: (d) Ester

Explanation

Nitroglycerin (glyceryl trinitrate) forms when glycerol reacts with nitric acid. It is the nitrate ester of glycerol, not a nitro compound, since the –NO₂ groups are joined through oxygen (C–O–NO₂).

It is a powerful explosive that is very sensitive to shock. Alfred Nobel made it safer by soaking it into earth, producing dynamite. In small doses it is also a heart medicine for angina.