You could say something along the lines of:
"Hey, Friend, what's so good about weed? Why are you always smoking it?"
If he's smoking it for medical purposes, then just drop it, but if it's illegal and he's doing it to "look cool", then I would further ask questions about it.
He is not coming big fella
Answer:
The answer would most likely be D.) Tomato. Was there any chart or photo attached to this question?