What is the active ingredient found in marijuana?

The active ingredient found in marijuana that is primarily responsible for its psychoactive effects is tetrahydrocannabinol, commonly known as THC. THC binds to cannabinoid receptors in the brain, leading to various psychological effects such as euphoria, relaxation, and altered sensory perception, which are often sought after by users of marijuana for recreational or medicinal purposes.

While CBD, another compound found in marijuana, is non-psychoactive and is noted for potential therapeutic effects without the high associated with THC, it is not the active ingredient that produces the psychoactive effects for which marijuana is most commonly recognized. THCA, or tetrahydrocannabinolic acid, is an inactive precursor to THC and does not produce psychoactivity until it is heated, a process known as decarboxylation. The option listed as ABC does not correspond to any recognized compounds in this context, making it irrelevant. Therefore, THC is the primary active ingredient that defines the characteristic effects of marijuana usage.