Which of These Best Represents Natural Selection

Which of these best represents natural selection?

A) Recessive albinism is more common among the Hopi of Arizona than in the general population of the U.S.
B) A gradual change in specific human mitochondrial DNA sequences occurs along the Nile river in Egypt.
C) ABO blood type frequencies are similar in northern Africa,southern Spain and the middle east.
D) Lactose tolerant alleles are very prevalent in herding populations that drink milk as a staple
E) Creutzfeldt-Jakob disease is found among families in Chile,Italy,Tunisia and Libya who were expelled from Spain during the Middle Ages.
F) A chick in a family of turkeys is born who has very unusual light brown plumage - no other relative has this phenotype.