Answer:
It is indeed SS.
Step-by-step explanation:
The reason for this being that each genotype, normally, has its matching pair, in some form or another, So the reason why it wouldn't be tt, is because this would mean that both alleles are recessive. It wouldn't be Ff, because one allele is dominant, and the other is recessive. Last, it wouldn't be XY because although XY is dominant, it's heterozygous.
You're welcome.
Problem solved