A satellite is moved from a low circular orbit of radius r to a higher circular orbit of radius 2r about the same planet. Which statement best describes how its kinetic energy K and gravitational potential energy U change once it has settled into the new orbit?
a) K decreases to one-fourth its original value, and U becomes less negative.
b) K increases to twice its original value, and U becomes less negative.
c) K decreases to one-half its original value, and U becomes less negative.
d) K decreases to one-half its original value, and U becomes more negative.