Question

tay-sachs is due to an autosomal recessive gene allele. two normal parents produce a child have tay-sachs. what can be concluded?
a; the parents are cousins
b; the woman was a carrier but the man was homozygous normal
c; there was a 50% probability that a child was to this couple would have tay-sachs
d; there must have been a mix up at the hospital because two normal people could not have that problem
e; both parents were heterozygous for tay-sachs