Answer
Choice C.
Work Step by Step
The correct choice is explained on page 976. Rotational periods of galactic stars are much shorter than can be explained by the visible matter at the center of these galaxies.
You can help us out by revising, improving and updating this answer.
Update this answerAfter you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.