The correct answer is C. Secondary sources arise when a historian analyzes and interprets primary sources to write about a topic or to support a thesis. Some examples of secondary sources are biographies, literary criticisms, book reviews, and interpretive newspaper articles.
When we are looking for sources is important to think about its reliability. To decide if a source is adequate is important to know who is the publisher and if he/her takes responsibility for the content, in addition, to know who is linking to the page, and if there are credible sites linking to this page.