Context: Read the passage. Then answer the question below.

The tallest sand dunes in North America are in Colorado. In this desert region, the top few inches of sand are usually dry, but the lower layers remain moist year-round.
Ord's kangaroo rats spend their entire lives in these dunes. They collect seeds from grasses and prairie sunflowers, and then bury the seeds in the moist layers of sand. Later, the rats come back to eat their buried seeds. The seeds absorb enough moisture from the sand that the kangaroo rats never need to drink water!
Figure: Great Sand Dunes National Park and Preserve in Colorado.
Which of the following best describes a community in the Great Sand Dunes?
A. the grasses and the prairie sunflowers
B. the Ord's kangaroo rats
C. the grasses, the water, and the sand dunes
Select the correct answer from the provided options and reply with the letter associated with it.
Answer: A