The correct answer is D. Elion and her colleagues were responsible for developing important drugs.
Explanation
The statement that best summarizes the main idea of the extract is D. "Elion and his colleagues were responsible for the development of important drugs." This can be affirmed because in the extract the author says that "Elion joined the Burroughs Wellcome Laboratories" clarifying that Elion began working in laboratories where medicines were manufactured. Later, the author refers that "Elion and Hitchings developed a variety of new drugs that were effective against leukemia, autoimmune disorders, urinary tract infections, gout, malaria, and viral herpes," in this part of the Extract is where it is directly mentioned what Elión and Hitchings did when they worked in the laboratory. Additionally, some of the diseases that were cured with the medicines they had developed such as leukemia, gout, malaria, among others, are mentioned.
