Many people I know have been doing surveys on drinking.
They start out with "do you drink?" and then the rest of the questions go on the assumption that you do drink.
I find this is an unfair assumption and likely to end up with biased answers.
Be open, keep in mind that not everyone will choose the same answer and make sure you vary your questions for all types of people.
Unique answers are often interesting and worth mentioning apart from the others by itself.
They start out with "do you drink?" and then the rest of the questions go on the assumption that you do drink.
I find this is an unfair assumption and likely to end up with biased answers.
Be open, keep in mind that not everyone will choose the same answer and make sure you vary your questions for all types of people.
Unique answers are often interesting and worth mentioning apart from the others by itself.