The answer is
Let's first represent alleles:
R - a dominant allele for round seeds,
r - a recessive allele for wrinkled seeds,
Y - a dominant allele for yellow seeds,
y - a recessive allele for green seeds.
The cross will look like this RRYY x rryy
So, all of the offspring will be heterozygotes (RrYy) with round seeds (Rr), yellow seeds (Yy).
