Question

question 11
the greatest source of both nitrogen and phosphorus entering chesapeake bay is
septic systems
agriculture
municipal and industrial wastewater
urban fertilizer runoff
natural sources

Explanation:

Agriculture involves the use of fertilizers rich in nitrogen and phosphorus. Run - off from agricultural fields is a major contributor to the nitrogen and phosphorus entering Chesapeake Bay. Other sources like septic systems, municipal and industrial wastewater, urban fertilizer runoff, and natural sources contribute less compared to agriculture.

Answer:

B. agriculture