Saving water in a rain barrel is an easy way to conserve one of our most important natural resources. The water that is stored in the barrel can be used for watering house plants or washing the car. Your pet will enjoy the rain water at bath time, too.

What is the author's purpose for writing this paragraph?
A) To sell rain barrels.
B) To raise money for the local swimming pool.
C) To explain the health benefits of using rain water.
D) To persuade people that using a rain barrel to conserve water is easy.