Conclusions From A Dihybrid Cross

Which of the following conclusions can be drawn from a dihybrid cross that produces a 9:3:3:1 phenotypic ratio?

I. The alleles of one gene assort independently of those of the other gene.

II. The alleles of the two genes exhibit a simple dominant-recessive relationship.

III. The organisms that were crossed were both homozygous for at least one of the loci in question.