Complete the sentence choosing the correct option. While many think the…

Key idea: the conjunction "while" introduces a contrast, so the clause that fills the blank must state something that contradicts the belief that the tobacco epidemic is solved.

Best completion: 37 million Americans still smoke -- including 21 percent of adults in Alabama.

• This sentence provides the necessary contrast by giving a current factual statistic that shows the epidemic is not solved.

• It fits grammatically after "while many think... is solved" because it supplies an opposing reality rather than repeating or restating the belief.

• It uses a concrete statistic, which makes the contrast clear and informative.

Why the other completions fail:

• The statement that the government had to be very strict is awkward and does not directly contradict the belief that the epidemic is solved; it fails to show the problem still exists.

• Saying people became aware only after serious diseases broke out is plausibly descriptive but does not directly oppose the idea that the problem is solved, and its phrasing is awkward.

• Claiming the problem was already solved years ago restates the mistaken belief instead of contradicting it, so it does not satisfy the contrast demanded by "while."