Huan made a chart to study for an exam about radio waves. A 2-column table with 1 row. Column 1 is labeled X with entries Changes the frequency of a wave; Is used by cell phones to transmit data. Column 2 is labeled Y with entries Changes the height of a wave; Is used by television stations for pictures.

Which headings best complete the chart?
Answer choices:
X: Phase
Y: Pulse

X: Pulse
Y: Phase

X: AM
Y: FM

X: FM
Y: AM