If the offspring of a cross show a 9/16 to 3/16 to 3/16 to 1/16 ratio (9:3:3:1), the parents of the cross have the genotypes
AaBb x AaBb
AaBb x aaBB
aaBb x aabb
aaBb x Aabb
As we have discussed in Dihybrid Cross -
Hene, the correct option is (a).