ANS:D - watts.

1. kgs (kilograms): Kilograms are a unit of mass in the International System of Units (SI). Mass refers to the amount of matter in an object and is typically measured in kilograms. However, kilograms are not a unit of power; they are used to measure the amount of substance an object possesses.
2. joules: Joules are a unit of energy in the International System of Units (SI). One joule is defined as the amount of energy transferred or expended when a force of one newton is applied over a distance of one meter. While joules are related to power (as power is the rate at which energy is transferred or converted), they specifically measure energy, not power.
3. newtons: Newtons are a unit of force in the International System of Units (SI). One newton is defined as the force required to accelerate a one-kilogram mass by one meter per second squared. Newtons are not a unit of power; they measure force.
4. watts: Watts are a unit of power in the International System of Units (SI). One watt is defined as one joule per second, representing the rate at which work is done or energy is transferred or converted. In the context of sound, power is measured in watts to quantify the rate at which sound energy is emitted or transmitted by a source.

In SI units, the power of sound is represented in watts. Watts (W) are the standard unit of power in the International System of Units (SI). Power is defined as the rate at which work is done or energy is transferred or converted. In the context of sound, power represents the amount of sound energy produced or transmitted per unit of time. Sound power, measured in watts, quantifies the rate at which sound energy is emitted or transmitted by a source. It is a fundamental parameter used to describe the intensity and loudness of sound waves.