# Which one of these statements is true about Copernicus

###### Question:

Which one of these statements is true about Copernicus?

a. His model included planetary orbits that were circular.

b. He believed that Ptolemy's ideas about the shape of orbits were correct

c. His model could not account for retrograde motion of Mars.

d. His model of the universe placed the Earth, rather than the Sun, at the center.

e. His model included planetary orbits that were elliptical.