Some coral reefs off the east coast of South America are starting to die off. Satellite images reveal great plumes of sediment washing out of the mouths of rivers. What can you conclude, if anything, about the relationship between these two factors?

A. Although the two factors coincide, they are not likely to be related.
B. Deforestation on land results in lower oxygen levels in the atmosphere, which stresses the reef.
C. Deforestation on land allows erosion to wash away topsoil, which smothers reefs.
D. Burning of the rain forest increases atmospheric carbon dioxide to levels toxic to reefs.