On a Texas Grassland, Coyotes (The Major Predator) Preyed on Burrowing

On a Texas grassland, coyotes (the major predator) preyed on burrowing rodents, which in turn fed on grasses and insects.Managers removed coyotes from the grassland, and a year later the grasses declined in biomass.This sequence of events suggests that control of energy flow in this food web was

A) top-down, with coyotes in control.
B) bottom-up, with grasses in control.
C) top-down while coyotes were present and bottom-up when they were gone.
D) bottom-up while coyotes were present and top-down when they were gone.
E) top-down for coyotes and rodents and bottom-up for grasses and insects.