The Most Significant Difference Between the Astronomical Theories of Ptolemy

The most significant difference between the astronomical theories of Ptolemy and Copernicus is

A) Ptolemy uses circular planetary orbits while Copernicus uses elliptical orbits.
B) Ptolemy's theory does away with many of the complexities of the Copernican theory.
C) Ptolemy's theory is Earth- centered, whereas Copernicus's is sun- centered.
D) Ptolemy's is not based on scientific evidence, while Copernicus's is.
E) Ptolemy's theory is sun- centered, whereas Copernicus's is Earth- centered.