Answer:
Option C, Both A and B
Step-by-step explanation:
A gateway drug is one which if consumed regularly will make the user daring enough to try much harmful drugs such as cocaine, marijuana etc. Hence, a gateway drug is one which opens gate for a person to use more harmful and varied drugs. Such as alcohol,nicotine etc.
Under the affect of gateway drug a person is unable to make right and conscious choices and hence he/she becomes impaired.
Thus, option C is correct