The Primary Purpose of Describing Planetary Orbits in Terms of Epicycles

The primary purpose of describing planetary orbits in terms of epicycles and deferents was to account for the

A) generally eastward motion of a planet compared to background stars while the whole sky appeared to move westward.
B) variation of brightness of a planet with time.
C) difference between the sidereal period and the synodic period of a planet.
D) pattern of direct and retrograde motion of a planet as it moved slowly against the background of stars.