Which of the following is a simple sentence?
A. Though some people believe a non-fatal snake bit can create immunity to snake venom, they have actually probably received only a dry bite during which the snake released little venom.
B. Snakes are important, but most people don't like them.
C. Pythons have become a problem in the Everglades; thousands released during Hurricane Andrew have naturalized in the environment.
D. Herpetologist Dr. Roan Stevens specializes in the study of exotic snakes native to tropical rain forests.