What could happen if one of the farmers used too much fertilizer on their crops?

A .The fertilizer could run off into the river, causing an overgrowth of algae, which decreases the amount of oxygen available for other organisms in the water
B .It would make the water supply better for everyone
C .No effect

I believe the answer is A: The fertilizer could run off into the river, causing an overgrowth of algae, which decreases the amount of oxygen available for other organisms in the water.

Why? Because the land that the farmer built his farm on is tilted and at the end of the land, there is a river meaning if the farmer uses too much fertilizer it could run down the tilted land and into the river, causing an overgrowth of algae, decreasing the amount of oxygen needed for the organisms living there, and leaving the water ruined for everyone.

I think you were talking about the 5.04 Unit Test: Earth and Environment for 7th graders on the online school, K12, as I had seen the same question, and seen the picture that goes along with the question.

If this is incorrect, please, don't refrain to tell me. Thank you.