D: Ethanol (C2H5OH). A drug whose use is accepted by the governments of most Western nations.

It is tolerated because it is relatively easily taxed, and its moderate use does not affect the taker's productivity. Alcohol consumption is a taxation positive behavior. People who drink in moderation still work, and continue to pay income taxes as well as paying very high taxes when they purchase alcohol. Taxation revenue would reduce if alcohol were abolished, so alcohol prohibition is not in the government's interest in a social democracy.

This contrasts with many other drugs.