Explanation:
They were formed by accretion
The object that a satellite revolves around is the <em>central body</em> of the system. <em>(C)</em>
For example:
-- The central body of the solar system is the Sun.
-- The central body for TV satellites, GPS satellites, weather satellites, and the International Space Station is the Earth.
-- The central body for Phobos and Deimos is Mars.
This should be a pretty easy question to answer by elimination, when you notice that "Orbit", "Period", and "Rotation" are not "Bodies".
