The correct answer is $\boxed{\text{chloroform}}$.
Chloroform is a chemical compound with the chemical formula CHCl3. It is a colorless, dense, and highly volatile liquid that is widely used as a solvent. Chloroform is also a powerful anesthetic and was once used in medicine, but it is now known to be a carcinogen and is no longer used for this purpose.
The melting point of chloroform is 209 K, which is equivalent to -73.5 °C. This means that chloroform will melt at a temperature of -73.5 °C and will turn into a liquid.
The other options are incorrect because they do not have the chemical formula CHCl3.
- Carbon tetrachloride has the chemical formula CCl4. It is a colorless, non-flammable liquid that is used as a solvent and refrigerant. The melting point of carbon tetrachloride is 250 K, which is equivalent to -23 °C.
- Chlorophenol has the chemical formula C6H5ClO. It is a white, crystalline solid that is used as a disinfectant and herbicide. The melting point of chlorophenol is 295 K, which is equivalent to 22 °C.
- Chloroethanol has the chemical formula C2H5ClOH. It is a colorless, flammable liquid that is used as a solvent and intermediate in the manufacture of other chemicals. The melting point of chloroethanol is 243 K, which is equivalent to -26 °C.