Assuming these options, since you didn't add any, here's the answer:
A. Green feathers
B. Yellow feathers
C. Long beak
D. Short beak
Considering
G = Green, L = Long, g = yellow, l = Short
The traits which are most likely to be observed in all the offspring of these parents are Green feathers and Long beak as they are dominant in comparison to the yellow feathers and short beak, which are recessive in this case.
We can say that this has occurred because of crossing over of the homologous chromosomes.