Deleterious Alleles (Lethal Recessives) Can Remain at Low Frequencies in Populations

Deleterious alleles (lethal recessives) can remain at low frequencies in populations because

A) mutation can alter the allele to decrease its lethality.
B) most individuals who carry the gene are heterozygous and do not suffer consequences of having two copies of the gene.
C) heterozygotes most often pass on the dominant allele.
D) many, but not all, homozygous recessive individuals die.