Natural sources such as volcanoes are the primary source of environmental chlorine.

• A. True
• B. Not sure
• C. They are the only source
• D. False

Answer: (D)

Chlorine in the environment comes from both natural processes and human activities, but volcanic emissions are not the main source. While volcanoes release chlorine, the total amount released by human activities—such as burning fossil fuels that emit chlorine-containing compounds, manufacturing and using chlorine-based chemicals, and waste incineration—often surpasses natural volcanic contributions. That means the idea that natural sources are the primary source overstates volcanism and overlooks the substantial impact of anthropogenic releases. So, the statement isn’t correct because human activities contribute a major portion of environmental chlorine, not natural volcanoes alone.