The two heterozygous parents were crossed and then the prospective offspring with recessive traits observed with 25% as described below.
Pq x Pq (heterozygous parental genotypes of mal e& female)
P q x P q (gametes)
PP Pq Pq qq (25% ---> recessive trait offspring)
Thus, the options (a), (c) and (b) are incorrect.
The two heterozygous parents were crossed and then the prospective offspring with recessive traits observed with 25%.
Therefore, the correct option is – d. 25%.