What, If Any, Evidence Did Galileo Have for the Law

Multiple Choice

What, if any, evidence did Galileo have for the law of inertia?

A) A smooth ball slows down when rolling uphill, and speeds up when rolling downhill, so it should maintain an unchanging speed on a level surface.
B) Noting that the length of the year does not change, he concluded that Earth must maintain an unchanging speed when moving around the sun.
C) Using a telescope, he observed meteors and comets moving at unchanging velocity through outer space.
D) All of the above.
E) He didn't have direct evidence, but proposed the law of inertia only because of the known failures of Aristotelian physics.