Question

when nitrogen and phosphorous runoff from agricultural areas, it can run into surface waters setting off a chain reaction that starts with an algal bloom and ends with an area of low oxygen. what do we call this process?
ecology
eutrophication

Explanation:

Eutrophication occurs when excessive nutrients like nitrogen and phosphorus from agricultural runoff enter surface - waters, causing algal blooms. As the algae die and decompose, oxygen is consumed, leading to low - oxygen areas. Ecology is a broader field and not the specific term for this process.

Answer:

B. Eutrophication