Dr. Burkholder hypothesized that Pfiesteria was associated with the massive die-offs of estuarine fish. Her hypothesis was supported when

A)Pfiesteria was shown to be capable of living within the climatic ranges of North Carolina.
B)a predicted increase in Pfiesteria populations coincided with a fish die-off.
C)new observations revealed Pfiesteria could kill laboratory fish.
D)a virulent toxin was isolated from Pfiesteria cultures grown in the laboratory.