Explanation
Correct answer: D.
Choice D is the best answer. The study isn’t definitive, but it says that Mimas’s wobbly rotation could be explained by the hidden ocean.
Why the other choices are wrong
Choice A
Choice A is incorrect. This choice goes too far beyond the information in the text. Rhoden’s team proposed that one moon of Saturn could have a liquid ocean beneath its surface, and that other moons should also be examined, but no one has confirmed anything.
Choice B
Choice B is incorrect. This choice conflicts with the text. Research has identified at least one sign—the unusual wobble in Mimas’s rotation—that might be due to a hidden ocean beneath its surface.
Choice C
Choice C is incorrect. This choice doesn’t reflect the text. The computer model studies “gravitational interactions,” which seem to account for the wobbly rotation of Mimas.