Which of the following statements is true regarding the responsibilities of reviewers?

Reviewers should identify the positive and negative aspects of a manuscript, and indicate where improvements are needed.

Reviewers are not supposed to turn down opportunities to review manuscripts even if they lack the relevant expertise.

Reviewers can make use of the information in a manuscript before it is published, giving them an advantage over competitors.

Reviewers should be an advocate for the author and to help convince the editor to publish the manuscript.