Which of the following drugs is most commonly considered illicit?

Marijuana is often perceived as an illicit drug, especially in contexts where its use is prohibited by law. This perspective has evolved significantly over time, as various jurisdictions have begun to decriminalize or legalize marijuana for both medicinal and recreational use. However, in the context of the question regarding commonly considered illicit drugs, marijuana remains a prevalent choice because it is still classified as illegal in many areas, leading to the widespread perception of it as an illicit substance.

Heroin, cocaine, and LSD are generally more universally regarded as illicit drugs due to their potential for misuse, severe health risks, and the legal repercussions associated with their possession and distribution. The context of legalization efforts and changing societal attitudes towards marijuana often leads to differing opinions on what is considered illicit, but the question suggests a traditional perspective where marijuana is still viewed in the realm of illegal substances.