In this task you will be given an answer to a question. You need to generate a question. The answer given should be a correct answer for the generated question.

Let me give you an example: This list contains the top 25 accounts with the most followers on the social photo-sharing platform Instagram. As of May 2018, the most followed user is Instagram's own account, with over 235 million followers. Selena Gomez is the most followed individual, with over 137 million followers. Ten accounts have exceeded 100 million followers on the site.
The answer to this example can be: who has the maximum number of followers on instagram
Here is why: The answer is talking about the Instagram accounts that have the most followers. The question asking about the maximum number of followers. So this is a good example.

OK. solve this:
Menthol cigarettes are constructed similarly to non-mentholated cigarettes, with menthol added at any of several stages during the manufacturing process. Menthol may be derived from distilled corn mint oil, or produced synthetically. While trace amounts of menthol may be added to non-mentholated cigarettes for flavor or other reasons, a menthol cigarette typically has at least 0.3% menthol content by weight. Lower-tar menthol cigarettes may have menthol levels up to 2%, in order to keep menthol delivery constant despite the filtration and ventilation designs used to reduce tar.
Answer:
where does the menthol in cigarettes come from