Why Is Newton's Version of Kepler's Third Law So Useful

Multiple Choice

Why is Newton's version of Kepler's third law so useful to astronomers?

A) It tells us that more- distant planets orbit the Sun more slowly.
B) It allows us to calculate distances to distant objects.
C) It explains why objects spin faster when they shrink in size.
D) It can be used to determine the masses of many distant objects.