You Are the Lucky Student of a Wacky Professor Who

You are the lucky student of a wacky professor who develops a time machine and he asks if you will test it with him.You get in and there's an immediate glitch-the date readout fails so that when you land you're not sure what era you're in.Your professor begins to panic,but you see something that tells you you're in the Cenozoic era.Which of the following could it be?

A) a rabbit eating a daisy
B) a water lily floating in a pond
C) masses of green ferns with dragonflies hovering above them
D) a bee pollinating a flower
E) many birds flying and roosting near the time machine