He diagram shows a device that uses radio waves. Two radio towers. The towers are equal distance apart with an arrow between them. The left tower is labeled X. The right tower is labeled Y. The arrow is pointing from Tower X to Tower Y.
What is the role of the part in the diagram labeled Y?

modulate, amplify, and send out waves
capture, amplify, and demodulate waves
change the amplitude and frequency of waves
change the pulse and phase of waves