Answer;
4. Peer-reviewed Journal Article
Step-by-step explanation;
-Peer-reviewed journals - Articles are written by experts and are reviewed by several other experts in the field before the article is published in the journal in order to insure the article's quality.
-Peer review means that a board of scholarly reviewers in the subject area of the journal, review materials they publish for quality of research and adherence to editorial standards of the journal, before articles are accepted for publication.