Which country is almost 5x the world average and almost 10x what would be sustainable?

Fa child has tay sach's disease, what would her parents' genotypes be? a) her father is heterozygous; her mother is heterozygous. b) her father is heterozygous; her mother is homozygous dominant. c) her father is homozygous dominant; her mother is homozygous dominant. d) her father is homozygous dominant; her mother is homozygous recessive.