Question

Review the text.
When fish waste builds in a tank, ammonia levels endanger the fish. Creating an aquaponic system eliminates the need for expensive filters and frequent water changes. Supplies include a rectangular plastic container, small houseplants, clay pebbles, and two plastic tubes.
Cut round holes the width of the tubes in opposite ends of the plastic container. Secure the tubes in the holes, sealing them against leaks. Place the pebbles in the container, and root the plants in them.
Position the free end of one tube in the fish tank, and connect the free end of the other tube to the tank's pump. Water should now flow from the tank, through the pebbles, and back to the tank. Good bacteria in the clay pebbles convert fish waste to nitrate, which is food for plants. Voilà! A self-cleaning tank and healthy plants!

Which best shows that the author's purpose is to explain to readers how to build an aquaponic system?

A. The author lists specific steps and materials that are needed for creating an aquaponic system.

B. The author argues that an aquaponic system eliminates the need for expensive filters and frequent water changes.

C. The author compares an aquaponic fish tank with ordinary fish tanks.

Answer 1

D. The author describes the benefits of an aquaponic system for both fish and plants.

A. The author lists specific steps and materials that are needed for creating an aquaponic system.