Answer:
The correct answer is option c. "nitrates".
Explanation:
Nitrates are among the most common contaminants and contributors of water pollution, particularly in rural areas. The presence of nitrates in drinking water is one serious problem because it could cause methemoglobinemia, or the "blue baby" disease. Additionally, the presence of nitrates in groundwater is related with the presence of other contaminants, such as bacteria or pesticides.
