Which sentence from "The Mighty Oak" BEST reveals the usefulness of oak trees? A. Most oaks are deciduous, but in climates such as those in the Southern United States they are evergreen, which means their leaves don't change color and fall off each year.

B. Oaks begin producing acorns when they are 20 years old; however, some will not produce their first acorns until the age of 50.

C. Oak trees provide habitat and food for thousands of types of animals and insects.

D. The oak has always been a symbol of strength because it grows so large and it lives for hundreds of years.