In the P generation, a tall plant was crossed with a short plant. Short plants reappeared in the F2 generation because
a. the allele for shortness becomes dominant in the F2 generation.
b. the alleles for both heights segregated when the F1 plants made gametes.
c. the allele for shortness becomes more common in the F2 generation.
d. the alleles for tallness begin to disappear in the F2 generation.
Answer: b