The communications of the ship were made inoperable by electromagnetic waves sent by the death star that were completely out of phase with attempted communications causing

Option D.

Explanation:

Your full question is attached in the picture below

Destructive interference occurs when two waves are out of phase, so they cancel each other. The resulting wave has amplitude zero.

The waves are usually of the same frequency, but opposite phase, so the maxima of one wave cancels with the minima of the other.

We can see in the second image an example of destructive interference.