In What Way Did Galileo Improve on the Physics of Aristotle

Multiple Choice

In what way did Galileo improve on the physics of Aristotle?

A) Galileo understood that no force is needed to keep an object moving in a circle at constant speed.
B) Galileo understood that "natural" (or unforced) motion occurs at constant velocity.
C) Galileo understood that a force is needed to keep an object moving at constant velocity.
D) Galileo understood that energy is always conserved in every physical process.
E) Galileo understood that the gravitational force acts between every pair of objects in the universe.