Which of the following is an example of a circannual rhythm?

• A. Mosquitoes are most active at dawn and dusk.
• B. Just as the sun sets, bats leave the cave in large swarms.
• C. Fiddler crabs exhibit courtship behavior based on the phase of the moon.
• D. In the heat of the day, most of the mammals at the zoo rest in the shade.
• E. Every spring robins gather in the park to build nests and reproduce.