Which of the following is used as an anaesthetic?

The option that is commonly used as an anaesthetic is CHCI₃, which is also known as chloroform. Chloroform is a colorless liquid with a sweet smell, and it was widely used as an anaesthetic in the past. It works by depressing the central nervous system and inducing a state of unconsciousness. However, chloroform has been largely replaced by other anaesthetics due to its potential to cause liver damage and other health problems. Other options, such as C₂H₅OH or ethanol, may be used for sedation or pain relief but are not typically used as general anaesthetics.