During the day in Lake Constance, the zooplankton D. hyaline departs f

OFFICIAL EXPLANATION

The presence of predators of zooplankton, feeding near the surface during the day, would suggest that D. galeata is consumed at a higher rate than D. hyaline. Therefore, if this choice were true, it would help resolve the apparent paradox that D. galeata grows and reproduces faster than D. hyaline, yet D. hyalian has the greater population.

A is incorrect. Nothing is said in the paragraph to show the relevance of the presence of other species of zooplankton to the relative population size of the two species. C is not correct. This information explains the slower growth and reproduction of D. hyaline, which is one aspect of the paradox; but it does nothing to show how D. hyaline can grow and reproduce more slowly and yet have the greater population. D is incorrect. Nothing is said in the paragraph to show the relevance to the paradox of D. galeata’s clustering under vegetation. E is also incorrect. More information on the faster reproduction of D. galeata does not show how, despite faster growth and reproduction, D. galeata has the lesser population.