If you notice that two waves combine and a part of the resulting wave has less light intensity than either of the individual waves, you're observing A. destructive interference. B. polarization. C. constructive interference. D. diffraction.
The correct option is A. Destructive interference is said to occur when two waves of equal frequencies and opposite phase merge in such a way that the negative displacement of one wave coincides with the positive displacement of the other thus cancelling each other out.
If you notice that two waves combine and a part of the resulting wave has less light intensity than either of the individual waves, you're observing destructive interference.
