What distinguishes constructive interference from destructive interference?

Constructive interference occurs when two or more waves meet and their amplitudes reinforce each other, resulting in a wave with a greater amplitude than that of the individual waves. This phenomenon is a key concept in wave interactions, illustrating how overlapping waves can combine to enhance the overall wave effect.

In essence, when the crests of one wave align with the crests of another, their energies add up, leading to increased amplitude. This is particularly important in various fields, such as acoustics and optics, where understanding how waves interact can lead to better designs and applications.

The other options are not correct because they either misrepresent the nature of wave interactions or limit the occurrence of constructive interference to specific scenarios that are not widely applicable. For instance, constructive interference is not restricted to sound waves, as it can occur with any type of wave, including light waves and water waves, making option C the clearly accurate choice.