Which of the Following Is True of F^ST, a Measure

Which of the following is true of F^ST, a measure of genetic distance between populations?

A) F^ST increases faster when subpopulations are small.
B) F^ST is useful to quantify how dramatically populations have diverged in their respective allele frequencies.
C) When F^ST = 0, allele frequencies are approximately the same from place to place.
D) all of the above