The unaffected carrier individual, is the one who has only mutated gene of the autosomal recessive disease.
The right answer is B and C individuals
The genes responsible for autosomal recessive (AR) transmitted diseases are localized on autosomes.
The mutated allele responsible for the disease is recessive on the wild allele; heterozygotes are healthy and the disease is expressed only in homozygotes.
Tay-Sachs disease is a neurodegenerative disease caused by a deficiency of hexosaminidase causing an accumulation of ganglioside GM2.