4. Which describes a nicotine-substitute product? O A product with nicotine, but without other harmful chemicals.
O A product that is similar to nicotine but has no negative effects.
O A product that contains the same chemicals as tobacco.
O A product that replaces the nicotine in a smoker's cardiovascular system.

A product with nicotine, but without other harmful chemicals.

Explanation:

When we give the so-called nicotine replacement therapy we aim to give the person nicotine but not the other harmful substances from the tobacco. This is because we want to get them off from nicotine but to do that we still need to give them nicotine for the process to work. So we at least pass the other harmful parts of smoking to help them with their adiction to nicotine.

i believe the answer is a

treatments and vaccines : )