When the best evidence is collected,what is the "gold standard" for research?

A) The randomized controlled trial (RCT) .
B) The peer-reviewed article.
C) Qualitative research.
D) The opinion of expert committees.

Individual RCTs are the "gold standard" for research.A peer-reviewed article is one that has been reviewed by a panel of experts;this is not a research method.Qualitative research is valuable in identifying information about how patients cope with or manage various health problems and their perceptions of illness.It does not usually have the robustness of an RCT.Expert opinion is on the bottom of the hierarchical pyramid of evidence.