The correct answer is D. chloropicrin.
Chloropicrin is a chemical compound with the formula CCl3NO2. It is a colorless, oily liquid with a pungent, tear-inducing odor. It is used as a tear gas, a chemical weapon, and a fumigant.
Ethane is a chemical compound with the formula C2H6. It is a colorless, odorless gas that is the simplest alkane. It is the main component of natural gas and is used as a fuel and a refrigerant.
Ethanol is a chemical compound with the formula C2H5OH. It is a colorless, flammable liquid that is the alcohol found in alcoholic beverages. It is also used as a solvent, a fuel, and a preservative.
Ether is a chemical compound with the formula C2H5OC2H5. It is a colorless, flammable liquid that is used as an anesthetic and a solvent.
All of these compounds are organic compounds, but only chloropicrin is a constituent of tear gas.