In the garden pea, yellow color (Y) is dominant to green (V), and round pod shape (R) is dominant to the constricted form (r). Considering both of these traits jointly in self-fertilized dihybrids (dihybrid cross), thepregeux appeared in the following numbers (9:3:3-1 ratio):
a. 556 yellow, round
b. 193 green, round
c. 184 yellow, constricted
d. 61 green, constricted