The diagram below shows positions of the Moon as it orbits the Earth. Half of the Moon's surface is lit by sunlight no matter what the Moon's position. But the amount of the lit surface visible from Earth varies with the Moon's position. Examine the diagram below, and answer the question that follows.

Which phase of the Moon is represented by position 4?
A.
waxing gibbous
B.
waning gibbous
C.
waxing crescent
D.
waning crescent