Which of the Following Statements Is True

Which of the following statements is true?

A) Scientists developed dietary recommendations for the U.S. population after analyzing results of a single American study, the Framingham Heart Study.
B) Scientists are unlikely to obtain money to conduct research, if they don't consider the opinions and beliefs of the people in agencies who fund such projects.
C) Scientists typically use different methods to conduct research, which explains why studies involving humans often have conflicting results.
D) Scientists have peer reviewers analyze the designs of their human research studies, because the peer-review process reduces research bias.