from "Flower-Kissers"

Which quotation supports the author's claim that hummingbirds lead solitary lives?
A. "They are extremely aggressive—mid-air fights during mating season are common, and they can reach speeds of 60 mph when divebombing an enemy."
B. "The birds seem to know which person is responsible for filling the feeder and will leave other members of the household alone."
C. "Unlike other birds, hummingbirds do not migrate as a group, but as individuals."
D. "Within a month, the babies are strong enough to take care of themselves."