Answer:D
Explanation:
Both parent are Heterozygous for the sickle cell allele.
Both parent have sickle cell trait in which the both posses one abnormal allele of the hemoglobin beta gene (AS heterozygous genotype)
When two AS parents mate, probability of giving birth to a sickle cell anemia child is 1/4
AS + AS= AA, AS, AS, SS