Question

artificial eutrophication is a process that occurs due to human activities. what causes artificial eutrophication? sewage and fertilizer runoff, sand and gravel, gasoline, oil

Explanation:

Artificial eutrophication is caused by excessive nutrients (like nitrogen and phosphorus) entering water bodies. Sewage and fertilizer runoff contain these nutrients. Sand/gravel, gasoline, and oil don't introduce such nutrients to cause eutrophication.

Answer:

A. sewage and fertilizer runoff