Question

intensity is a measure of a sound waves
a energy.
b wavelength.
c frequency.
d speed.

Explanation:

Sound wave intensity is defined as the power carried by sound waves per unit area in a direction perpendicular to that area. Power is related to energy (as power is energy per unit time). Wavelength is related to the spatial period of the wave, frequency to the number of oscillations per second, and speed to how fast the wave propagates. Intensity specifically measures energy (as it's about the power which is energy - related quantity for the wave).

Answer:

A. energy