Which one of the following crosses would have ratio 1 : 1 : 1 : 1 ?

Which of the following crosses would result in 1 : 2 : 1 F_(2) ratio ?

Which one of the following crosses shows phenotypic ratio of 3:1?

Which one of the following gates will have an output of 1 ?

The genotypes of a plant variety were TtHh, Tthh, ttHh and tthh, where T = tallness and H= hairy stem. Which one of the following crosses would produce progeny giving a phenotypic ratio approximately 1:1:1:1 ?