Which of the following can be used for denaturation of ethyl alcohol?

Methyl alcohol can be used for denaturation of ethyl alcohol. 

The alcohol produced for industrial purposes is made unfit for drinking by adding poisonous substances like methanol to it. Such alcohol is called denatured alcohol. This prevents the misuse of alcohol. If a person consumes denatured alcohol, it results in coagulation of protoplasm causing severe nausea, blindness and even death. Methanol's toxicity is due to its metabolic products, it is poisonous.