In which scenario would directional stabilization be most likely to occur?

Directional stabilization is a form of natural selection that occurs when environmental pressures consistently favor one extreme of a trait within a population, leading to a shift in that direction over generations. In the context of the options provided, consistent environmental pressure would create a scenario where individuals with traits that are advantageous under those pressures are more likely to survive and reproduce. This would ultimately lead to an increase in the frequency of those advantageous traits within the population, demonstrating directional stabilization.

For instance, if a population of birds were consistently experiencing changes in their environment that favored larger beak sizes, individuals with larger beaks would have a better chance of accessing food sources. Over time, the population would show a trend toward larger beak sizes, illustrating how directional stabilization occurs under continuous environmental pressure.

Thus, the correct answer reflects the relationship between consistent environmental pressures and the evolution of specific traits within a population.