Answer:
Illegal Drug
Step-by-step explanation:
To be truthful, it is proven that certain prescription medicine's and illegal drugs affect brain activity, but seeing as how only some, not all, prescription medicine's affect brain activity, the only correct answer for this is illegal drugs, because ALL illegal drugs affect the brains activity. For example, Marijuana causes a calm and "Happy" feeling. Cocaine causes accelerated brain aging, blood vessel damage, and cognitive damage. Another example is heroin, which causes hallucinations, which are caused by a chemical in the brain being released.