determine the genotypes of the two parents: A) a walnut crossed with a single produces offspring that are ¼ walnut, ¼ rose, ¼ pea, and ¼ single. B) A rose crossed with a walnut produces offspring that are 3/8 walnut, 3/8 rose, 1/8 pea, and 1/8 single. C) A rose crossed with a pea produces five walnut and six rose offspring. D) A walnut crossed with a walnut produces one rose, two walnuts, and one single offspring.