How Could Heavily Fertilized Lawns Contribute to Cyanobacterial Blooms in Lakes

Multiple Choice

How could heavily fertilized lawns contribute to cyanobacterial blooms in lakes and oceans?

A) Run-off from the lawns will get into the water system, leading to large amounts of nitrogen that can be used by cyanobacteria in water systems.
B) Nutrient-rich grass will be mowed down, with grass clipping bits eventually washing into sewer systems and into larger bodies of water. These grass clippings will serve as a nutrient source for cyanobacteria, leading to blooms.
C) Large amounts of fertilizer will lead to excessive production of greenhouse gases (like CO₂) from grass in lawns. Excessive CO₂ production will lead to large blooms of cyanobacteria in water systems.
D) Fertilizers contains compounds that encourage the production of bacteriochlorophylls; after rain, fertilizers get into water and are used by cyanobacteria. 
E) They won't-the two systems are completely unrelated. How could grass in lawns contribute to effects in lakes and oceans?