Read the excerpt below. Which of the following statements best summarizes the main idea of the excerpt?
In 1944 Elion joined the Burroughs Wellcome Laboratories (now part of GlaxoSmithKline (a company that makes prescription medicines)). There she was first the assistant and then the colleague of Hitchings, with whom she worked for the next four decades. Elion and Hitchings developed an array (variety) of new drugs that were effective against leukemia, autoimmune disorders, urinary-tract infections, gout, malaria, and viral herpes.

Select one:
a. Elion believed that new drugs could be developed to help people.
b. Elion had to work for Hitchings because she was a woman.
c. Elion worked hard for more than 40 years to earn money for retirement.
d. Elion and her colleagues were responsible for developing important drugs.