Answer:
d
. Because Susan’s diagram is showing that the half of the Moon that is facing the sun is lit by the sun, and the other half is dark
Explanation:
We can see on the diagram on the left side arrows that show the way from which sunlight appears.<u> It only lights up the left side of the sun, while the right one stays dark.</u>
<u>The moon does not produce any light or energy on its own, so only the side that is facing the Sun at the moment is lit up. </u>That is also the only side we can see from the Earth.
Because of the way and pace Earth and moon move through space and around their own axis, we can only constantly see only one side of the moon. The other side always stays dark, and it is often called the “far side of the moon”.
The position of the sun and moon also determine the phases of the moon we see from the Earth. If more of the moon is visible, that means the moon is positioned to directly face the sun and be lit up. If we don’t see much, the sun lights up only that portion of the moon.