Which of the Following Observations of the Motions of the Large

Which of the following observations of the motions of the large moons of Jupiter did Galileo find MOST significant?

A) Their motions are counterclockwise (viewed from the north) , just like the orbits of the planets.
B) Their orbits were elliptical, just like Kepler predicted.
C) Their orbits obeyed Kepler's second law.
D) The moons farther from Jupiter had longer periods, just as Copernicus had discovered for the planets around the Sun.