Concept:Crossing two genetically different homozygous lines produces offspring that are heterozygous.
Explanation:Homozygous lines have identical alleles for a trait, such as
AA and
aa.
When these two homozygous lines are crossed, each parent contributes one allele to the offspring.
The resulting
F1 generation has the genotype
Aa, which is heterozygous.
This method of crossing two distinct homozygous parents is known as hybridization.
Inbreeding, introduction, and selection do not directly create heterozygous populations from homozygous lines.
Therefore, the breeding method described is hybridization.
Answer:D. hybridization