Use the image to answer the question.
An illustration titled Coral Anatomy shows three coral polyps affixed to a base labeled D. The long, thin arms extending from each coral are labeled C. A blow up of the tissue of a long, thin arm identifies a row of cells containing small darts labeled A. Another row of algae cells is labeled B.
Which is the part of the coral that is built up over thousands of years into a reef?
(1 point)
Responses
B
A
C
D