Witch substance might lead to potentially dangerous addictions if abused?

Explanation:

These medications are weaker but they can develop an addictive behaviour, because these don't require a medical prescriptions, they are free to buy. Most common example is addiction development using over-the-counter sedative medication or pain-killers like acetaminophen and ibuprofen, which help people to feel relaxed.

It's important to use these medications only when is required, because their free access, and the excess of them can lead to addiction.

this would and i think the answer is d