Brittany and Jarod Have Been Trying to Have a Second

Multiple Choice

Brittany and Jarod have been trying to have a second child for 10 years.They have one healthy child,but Brittany has had four early,spontaneous abortions.The most likely explanation for the many pregnancy losses is that Brittany and Jarod

A) are not having sex frequently enough.
B) are each heterozygous for lethal alleles of the same gene.
C) are each homozygous for lethal alleles of the same gene.
D) have different alleles for all of their vital genes.