The model below shows the Moon at one position in its orbit around Earth. The white half of the Moon represents the part of the Moon that is lit up by the Sun.

Although the Moon appears to shine, it does not emit light. Instead, we can see the Moon because it is lit up by the Sun.

Explanation:

The part of the Moon that is both sunlit and facing Earth is called the Moon's phase.

As the Moon orbits Earth, the Moon's phase changes. The model below shows the Moon's phase at eight positions in its orbit. The smaller moons closer to Earth show where sunlight hits the Moon. The larger moons farther from Earth show how the Moon will look during that phase.

i think a) betsy can donate only blood to mark is correct because, mark and betsy have the same blood type. whereas nobody else has b+ blood so betsy can't donate to them.