Tobacco acts as a stimulant by releasing into the system. answer carbon monoxide adrenalin dopamine serotonin

Tobacco acts as a stimulant by releasing Nicotine into the system. Nicotine is considered as a highly-addictive drug that can also trigger the release of neurotransmitters, hormones and neuromodulators. When the person has been exposed to Nicotine, the body is being stimulated to release dopamine, adrenaline, and other neurotransmitters. Dopamine, which is mainly released by the brain, works as the source of motivation and pleasure. With constant exposure to nicotine and dopamine being released often in the system, this makes the body become dependent, thus, resulting in addiction. 

The answer might be d