Question

what causes different portions of the moon to be visible to earth at different times of the month? moon’s orbit around the earth. earth’s rotation earth’s orbit around the moon. moon’s rotation

Explanation:

The phases of the Moon (different visible portions) occur because the Moon orbits the Earth. As the Moon moves in its orbit, the portion of its illuminated side (by the Sun) that faces Earth changes. Earth’s rotation causes day - night cycles, not Moon phases. Earth orbits the Sun, not the Moon. The Moon’s rotation is synchronous (same rate as its orbit around Earth), so it doesn't cause the phase changes. So the correct reason is the Moon’s orbit around the Earth.

Answer:

Moon's orbit around the Earth.