When two different waves undergo complete, constructive interference, which of the following increases?

A. Speed

B. Frequency

C. Wavelength

D. Amplitude

The correct option is (D) Amplitude

Explanation:

Constructive wave interference is a wave interference which occurs when in phase waves meets with each other and forms a new wave with greater amplitude.

Let's suppose we have two waves with the same amplitude 2. The resultant wave would have an amplitude 4. It's just like the addition operation on the amplitude of the waves. If one wave has the amplitude 0.5 and other wave has an amplitude 3, the resultant waves would have the amplitude 3.5 in the case of constructive interference.