lead arsenic mercury aluminum
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: When chemicals in the atmosphere dissolve in water droplets, they precipitate with the water and pollute water reservoirs on Earth. The pollutants enter the food chain when aquatic organisms absorb them. Which of these pollutants eventually contaminates fish after coal is burned?
Possibilities:
- lead
- arsenic
- mercury
- aluminum

mercury