1 Scientists from the National Institutes of Health have identified an antibody from an HIV-infected
person that potently neutralized 98 percent of HIV isolates tested. This includes 16 of 20 strains
resistant to other antibodies of the same class. The remarkable breadth and potency of this antibody,
named N6, make it an attractive candidate for further development to potentially treat or prevent HIV
infection, say the researchers. The scientists, led by Mark Connors, M. D., of NIH's National Institute of
Allergy and Infectious Diseases (NIAID), also tracked the evolution of N6 over time to understand how it
developed the ability to potently neutralize nearly all HIV strains. This information will help inform the
design of vaccines to elicit such broadly neutralizing antibodies.
1. Which of the following best establishes the main idea of the passage as a whole?
A) NO CHANGE
B) 16 of 20 strains of HIV are resistant to other antibodies of the same class
C) The scientists tracked the evolution of N6 over time
D) The NIH does not approve of testing antibodies on HIV-infected patients,

Is the answer A, B,C or D