Final answer:
Scenario A (h^2=0.9; S=0.6) will produce the largest response to selection, as its product of heritability and selection differential is the highest among the given scenarios.
Step-by-step explanation:
The scenario that will produce the largest response to selection is Scenario A (h^2=0.9; S=0.6). The response to selection in a population can be calculated using the formula R = h^2 × S, where R is the response to selection, h^2 is the heritability of the trait, and S is the selection differential. Heritability is a measure of how much of the variation in a trait is due to genetic factors, while the selection differential is the difference between the mean phenotype of the selected individuals and the mean phenotype of the original population.
In Scenario A, the product of h^2 and S is 0.9 × 0.6 = 0.54, which is the highest among all the given scenarios. Therefore, Scenario A is expected to result in the largest change in trait frequency due to selection.