In Which of the Following Examples Has Communication Occurred? (Check

In which of the following examples has communication occurred? (Check all that apply.)

A) A bird gives an alarm call when a hawk approaches, but no other birds are in the area.
B) A bird sings from the top of a tree in its territory attracting a female of the same species to it.
C) A bird sings from the top of a tree in its territory keeping other birds of the same species from trespassing.
D) An ant lays down a trail of pheromones that other ants follow.
E) A waggle dancing bee feeds some of the nectar she is carrying to bees attending her dance; they now know what type of flowers she has visited.