Why does the moon revolve around the earth instead of revolving around the sun as the planets do ?

Question

$\begin{array}{1 1} (a)\;\text{uniform gravitational field exists between earth and moon} \\ (b)\; \text{gravitational field changes from place to place} \\ (c)\; \text{the velocity of moon is perpendicular to the direction in which the earth's gravity acts} \\ (d)\; \text{all the above} \end{array}$