The most accurate response regarding how the distribution curve of body lengths for a population of fish changes after a predator preys on both extremes of body length (short and long) is:
The curve becomes narrower and taller.
This outcome occurs because the predation eliminates individuals from the extremes of the distribution, leading to a concentration of body lengths around the average. As a result, the distribution becomes more centered, or "narrower," and the height of the curve increases due to a higher proportion of the population falling within a specific range of body lengths.