My best guess would be A
Please put me as a Brainlier
it could effect you because you could have one of the best times of your life!! but in all jokes aside most substances are unsafe to use and or addictive, however is you use non addictive safe drugs like lsd or weed you should be fine however i dont recommend it considering its illegal.
Answer:
A.Carbon Monoxide
Explanation:
Carbon Monoxide is a, colorless, odorless, poisonous gas produced when tobacco burns
