What must be the genotype of a couple that has a 100% chance of producing offspring that areheterozygous for the PTC taster gene?

A taster gene is a dominant trait. The probable gene of the parents that is more likely to produce 100% heterozygous offspring are:
Parent 1- TT (homozygous taster)
Parent 2- Tt (heterozygous taster)
When these genotypes TT X Tt are crossed the results are:
TT, TT, Tt, Tt
TT- 50% homozygous taster of PTC
Tt- 50% heterozygous taster of PTC