I want to know the answer to the following question:
The protesters were unhappy with the pollution in what body of water?
All the background I'm provided with is that "On October 17, 1987, about 3,000 Armenians demonstrated in Yerevan complaining about the condition of Lake Sevan, the Nairit chemicals plant, and the Metsamor Nuclear Power Plant, and air pollution in Yerevan.". Is that enough to answer the question?