The correct answer is C. The zygote is a single fertilized egg cell that the embryo develops from. This one cell possesses one copy of DNA that is going to be passed to all other cells in the embryo because all other cells of the embryo develop through mitotic divisions of the zygote. Therefore, if a mutation happens in the zygote DNA, all of the cells in the embryo are going to have it as well.
Its a 50/50 so two of there kids will have blue eyes and two will be brown eyes but the children with brown eyes with be heterozygous for blue eyes and same thing with the brown eye children