How is a less-intense wave different from a more-intense wave? It has fewer decibels.
O It has a higher pitch.
O It has more volume.
It has more energy.

It has fewer decibels.

Explanation:

In a sound-wave, the intensity is defined as the power carried by the wave. The decibel is a measure of the ratio between two quantities. And in acoustics is used as the unit of the sound pressure level, which is related to the intensity of the wave, then:

As the intensity increases, we also should notice an increase in the decibels.

How is a less-intense wave different from a more-intense wave?

The less-intense wave has fewer decibels.

it is very well related to a lot of things but with my limited knowledge i can confidently say that the answer is space.