Genetics..please help me sooo urgent!!!!!!!!!!!!!!!!!!!!!!!!!!

In peas the allele for round seed (R) is dominant over the allele for wrinkled seed (r). The allele for yellow seed (Y) is dominant over the allele for green seed (y).
If two pea plants with the genotypes YyRr and Yyrr are crossed together, what ratio of phenotypes is expected in the offspring?
A. 9 round yellow : 3 round green : 3 wrinkled yellow : 1 wrinkled green
B. 3 round yellow : 3 round green : 1 wrinkled yellow : 1 wrinkled green
C. 3 round yellow : 1 round green : 3 wrinkled yellow : 1 wrinkled green
D. 1 round yellow : 1 round green : 1 wrinkled yellow : 1 wrinkled green
(1)


which alleles can i use??
YR and yr / Yr and yr??
is that it?
i cant get the answer.. plz help me..!!

Set up a 4 x 4 Punnett Square with YR, yR, yr, and Yr down one side and Yr, yr, Yr, and yr down the other side. Complete the Punnett Square. You should end up with the following genotypes:
YYRr
YyRr
Yyrr
YYrr
YyRr
yyRr
yyrr
Yyrr
YYRr
YyRr
Yyrr
YYrr
YyRr
yyRr
yyrr
Yyrr

I ended up with a 3 ry: 1 rg: 3 wy: 1 wg ratio, making it option C.

YyRr x Yyrr will give
YYRr (Round yellow)
YyRr (Round yellow)
Yyrr (Wrinkled yellow)
YYrr (Wrinkled yellow)
YyRr (Round Yellow)
yyRr (Round green)
yyrr (Wrinkled green)
Yyrr (Wrinkled yellow)

So the correct answer is C.

C