How do the effects of nutrients in upwellings compare to the effects of nutrients from agricultural ...

How do the effects of nutrients in upwellings compare to the effects of nutrients from agricultural runoff?
 
  A) Both negatively impact marine ecosystems by causing hypoxia as a result of eutrophication.
  B) Nutrients from agricultural runoff tend to positively impact marine ecosystems by delivering nutrients that support healthy levels of marine productivity, while upwellings tend to harm marine ecosystems by causing hypoxia as a result of eutrophication.
  C) Upwellings tend to positively impact marine ecosystems by delivering nutrients that support healthy levels of marine productivity, while nutrients from agricultural runoff tend to harm marine ecosystems by causing hypoxia as a result of eutrophication.
  D) Both positively impact marine ecosystems by delivering nutrients that support healthy levels of marine productivity.