Answer:
C
Explanation:
Assume that allele A is the dominant allele that produces the dominant phenotype (tall) in plants that have at least one allele A, and allele a is the recessive allele that produces the recessive phenotype (short) in plants that have two alleles a.
In the parental generation, a true-breeding tall plant has the AA genotype (phenotype: tall), and a true-breeding short plant has the aa genotype (phenotype: short).
We have the Gregor Mendel's cross as in the image attached here.
All of the F1 generation (offspring plants) have the Aa heterozygous genotype, and therefore, they are all tall.
The answer is c (the offspring plants have a genotype that was different from that of both parents).
