Which of the following represents one full orbit of the moon?

Question

The question is, is a full orbit of the moon considered from a perspective of the Earth or is it a (relative) position based on Earth's position relative to the sun? Look at the following jpg (I created it myself so easy on the critique) and please tell me which of these represents one full orbit of the moon. You can just answer A or B if you want. If neither of my ideas is correct you can correct me as well!

http://cid-f197f38050172b7f.skydrive.live.com/self.aspx/test/moon.jpg

Answer 1

I'd say the award for most confusing question would go to you, were there such a thing.

Since the question is worded in a way that suggests you're asking about revolutions, the answer would be A, assuming that in the second position, it has already made a full revolution. However, if you're talking phases, the answer would be B, since they have to do with the reflection of the sun's light off the surface of the moon.

Something tells me you might have meant phase rather than revolution and that's why I answered in both accounts.

Answer 2

The top one that is with respect to the stars (the fixed frame reference) that takes 27 days is the full orbit. The other one (synodal) takes 29 days roughly and is the lunar month of counting phases (newmoon to newmoon) that is in vogue in Indian system.

Answer 3

The sidereal orbital period is the basic one when you're doing physics.

Answer 4

The one on the top would be one full rotation. The moon is orbiting the earth so it is from earth's perspective not the sun's.