Choose the correct answer to complete the paragraph about the acceptance of the heliocentric model. In the second century BCE, the Greek astronomer Ptolemy tried to explain the backward movement of the planets by using a solar system model that included
. For centuries, this was the accepted model. During the Renaissance, Nicholas
discovered the old heliocentric model of Aristarchus. In Aristarchus’s model, the rising and setting of the Sun was explained by the movement of the
.
.