Use of synthetic fertilizers often leads to the contamination of groundwater with nitrates. Nitrate pollution is also a suspected cause of anoxic "dead zones" in the ocean. Which of the following might help reduce nitrate pollution?a) growing improved crop plants that have nitrogen-fixing enzymes.
b) adding nitrifying bacteria to the soil.
c) adding denitrifying bacteria to the soil.
d) using ammonia instead of nitrate as a fertilizer.

Option a) is correct

Explanation:

Growing improved crop plants that have nitrogen fixing enzymes

Nitrate pollution occurs because of the introduction of excessive amounts of nitrogen to ground water and surface waterUse of synthetic fertilizers has resulted in high levels of pollution and eutrophication of lakes and rivers When nitrogen fertilizers are leached deep down into the soil they cause serious pollution problemsPlants that can do nitrogen fixation include members of family FabaceaeThe symbiotic association between legumes and Rhizobium is the most important nitrogen fixing association; rhizobia bacteria convert nitrogen gas to ammonia and this process is called nitrogen fixation