Which chemical is often referred to by the street name "Crank"?

The street name "Crank" refers to methamphetamine, which is a powerful central nervous system stimulant. Methamphetamine is known for its potential for addiction and its various forms, including powder and crystal. It is often associated with increased energy, euphoria, and alertness, which are some of the reasons it is popular in illicit use.

Understanding the context of drug culture and slang is essential for recognizing different substances, as drugs can have varying effects and potencies. Methamphetamine, in particular, is notable for its wide circulation in various forms and the distinctive terminology associated with its use.

The other substances listed, while they have their own street names, do not commonly use "Crank" to refer to them. Cocaine, heroin, and fentanyl each have different mechanisms of action, effects, and implications for use, separate from the context of methamphetamine's reputation in recreational use.