The correct answer is A.
The best way to refuse an offer to smoke or do drugs is to firmly say no. You need to make it clear to the person or people offering that you do not want to take anything. You need to be firm and assertive, not aggressive or passive. So firmly say no.
The second question is False. There are many disadvantages of negative peer pressure besides having questionable friends. Your self esteem can be affected, you could end up being bullied, you could make wrong decisions that end up being hurtful to you and others and so forth.