In the year 2500, five male space colonists and five female space colonists (all unrelated to each other) settle on an uninhabited Earthlike planet in the Andromeda galaxy. The colonists and their offspring randomly mate for generations. All
ten of the original colonists had free earlobes, and two were heterozygous for that trait. The allele for free earlobes is
dominant to the allele for attached earlobes.

Which of these is closest to the allele frequency in the founding population?
A) 0.4 a, 0.6 A

B) 0.5 a, 0.5 A

C) 0.2 a, 0.8 A

D) 0.8 a, 0.2 A

E) 0.1 a, 0.9 A

(please explain)