The earth orbits the sun once a year and the moon orbits the earth about once a month. From the earth you can observe the changing phases of the moon. If an observer stands on the moon and looks at the earth, what would be the period of the phases of the earth seen by that observer?
A. Same period as the phases of the moon
B. A little longer than the period for the phases of the moon
C. A little shorter than the period for the phases of the moon
D. About 1 year