Correct Option: B

Tear gas, formally known as a lachrymatory agent, is a possibly lethal chemical weapon that stimulates the corneal nerves in the eyes to cause tears, pain, and even blindness. The compound 2chlorobenzalmalononitrile (chemical formula: C10H5ClN2), is the defining component of a "tear gas" commonly referred to as CS gas, which is used as a riot control agent.