Answer:
B. He controlled pollination.
Step-by-step explanation:
The statement that best described Mendel's experiment is that he controlled pollination.
Mendel carried out several experiments to study the pattern of inheritance of traits in pea plant. He cross bred phenotypically different pea plants and he was able to make certain conclusions based on how traits are inherited. He could only have been able to crossbreed plants by controlling pollination in the plant.
Mendel did not begin with hybrid plants. A hybrid plant is a product of crossbreeding two different organisms and often carry a mix of traits from the two organisms. Rather, Mendel started with pure breeding pea plants.
Mendel also observed more than one generations. He advanced several of the crossbreeding experiment to F2 generation before propounding the laws of genetics.
Mendel used a plant with short life cycle. They reproduce fast and as such, he was able to study different generations within a short period.
The correct option is B.