Answer:
D.) He was able to prove that Ptolemy's theory that the moon had a smooth, polished surface was true.
Step-by-step explanation:
"But peering at the magnified moon, Galileo saw that Ptolemy was wrong. He saw that the moon's surface was, as he later wrote, '"Rough and uneven"' with '"Lofty mountains and deep valleys,'" similar to the surface of the Earth."
Students of K12, please reference "The Human Odyssey, Our Modern World, 1400 to 1914. I retained this information from page 313.
I hope this helped! Have a blessed day! :)