Which of the Following Is NOT an Example of a Trait-Mediated

Which of the following is NOT an example of a trait-mediated indirect effect?

A) The presence of raptors causes squirrels to forage at night instead of during the day.
B) Greater numbers of aspen trees grow in areas where predation risk from wolves prevents elk from browsing.
C) Grasses increase because the presence of spiders has reduced grasshopper foraging.
D) Zooplankton abundance in a pond increases because piscivorous largemouth bass cause small fish (zooplanktivores) to take refuge in pond margins away from zooplankton.