Which of the following is false? a. if a genetic disease reduces fertility and the allele that causes the disease offers no other advantage, the allele will likely eventually disappear, due to natural selection. b. natural selection does not favor individuals who are homozygous for the sickle-cell allele, because these individuals typically die before they are old enough to reproduce. c. individuals who are heterozygous hba/hbs are protected from malaria, and this is why sickle-cell disease persists in wetter, mosquito-prone regions in africa. d. in regions where malaria does not occur, individuals who are heterozygous hba/hbs have a fitness advantage over those who are homozygous for the normal hemoglobin allele (hba).