"The Earth spinning on its axis helps us determine a measurement of time." Which sentence from the article provides the BEST support to the statement above?

a
(A) Like all planets, Earth has two types of motion, orbit and spin.
b
(B) One full trip around the sun takes Earth about 365 days, which is equal to one year.
c
(C) The axis is an imaginary line that runs through Earth’s center.
d
(D) Earth completes one rotation in 24 hours, which is equal to one day.