Read the article and answer using the possible answers provided.

The correct answer is D. Dr. Salk has traveled and given the polio vaccine to children in foreign countries.

Explanation:

The other three options are stated on the second paragraph, however, the passage does not say anything about Dr. Salk traveling to give the polio vaccine to children in foreign countries.

answer: the tobacco industry has traditionally been one of the most important industries in north carolina and a backbone of the state's agricultural heritage. yet as the north carolina economy continues to transition from an agricultural economy to a manufacturing and, increasingly, service-based economy, the industry faces new challenges, both at home and abroad

explanation:

the novel is told in flashback