How to reduce engine noise?

A)
By using chevron nozzle
B)
By using high velocity jet
C)
Using small diameter and high velocity jet
D)
Higher exhaust jet with less diameter of exhaust

Correct Answer :   By using chevron nozzle


Explanation : Chevron nozzle is used to reduce the engine exhaust aural signatures. Chevron nozzle accompanies saw tooth pattern at the trailing edge. High velocity jet will produce more noise due to air shear layer effects.