According to Copernicus, Retrograde Motion for Venus Must Occur Around

According to Copernicus, retrograde motion for Venus must occur around

A) greatest elongation, when the planet is farthest from the Sun.
B) inferior conjunction, when it passes between us and the Sun.
C) opposition, when the planet lies opposite the Sun in the sky.
D) quadrature, when the planet is 90 degrees away from the Sun.
E) superior conjunction, when the planet is on the far side of the Sun.