Which Would Be More Likely to Cause Illness: a Water

Which would be more likely to cause illness: a water sample that tested positive for coliforms or one that tested positive for E. coli O157:H7?

A) Both would be equally capable of causing illness because all coliforms cause illness.
B) The coliform-positive sample would be more likely to cause illness. Coliforms are inherently more pathogenic than the weak O157:H7 lab strain of E. coli.
C) The E. coli O157:H7 sample would be more likely to cause illness. This strain of bacterium is highly pathogenic and capable of causing kidney damage.
D) Neither; there is usually a small amount of coliforms (including E. coli O157:H7) in all water.
E) The coliform-positive sample would be more likely to cause illness. Coliforms indicate the presence of fecal contamination, which always leads to illness.