Industries have built many oil and gas platforms off the Texas coast. Coral reefs have formed underwater on many of the platforms. The formation of coral reefs on the platforms is — A. harmful because it increases competition between coral reefs.
B. harmful because it decreases the likelihood that coral reefs will form in flat, muddy areas.
C. helpful because it offsets the number of coral reefs lost to pollution.
D. helpful because it prevents coral reefs from forming in flat, muddy areas.