At position C, moon is half lightened, while at B it's full moon so at the path between B and C most of the area visible to earth should be white. So it has to be either C or E.
Figure 1 shows Earth, the Sun, and five different possible positions for the Moon during one full orbit. It is important to recall that one half of the Moon’s surface is illuminated by sunlight at all times. For each of the five positions of the Moon shown below, the Moon has been shaded on one side to indicate the half of the Moon’s surface that is NOT being illuminated by sunlight. Note that this drawing is not to scale.
Match the moon position (A-G) with the picture that correctly shows the phase of the moon in that position.
At position A, you would see?
HOW do i do this???
When the Moon is at position A, the situation is approximately the following.
As you can see, the observer sees a little shadow on the left of the Moon (between C and D), while the right edge is fully illuminated.