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Eutrophication in the Chesapeake Bay along the eastern edge of Maryland bas resulted in low oxygen levels in the water and alteration of food webs. The cause of this eutrophication appears to be pollution that contains high levels of:

1. nitrogen

2. carbon

3. phosphorus

4. sulphur

Which of the above is/are correct?

A)  1 and 3           

B)  2 and 4

C)  1, 2 and 3                    

D)  All of these