If the author of a source is unknown, the information you should include in the parenthetical citation is B) Shortened title of work.
In case you are citing a web page, an article, or a chapter, their names must come inside the parentheses, between double quotation marks, and followed by the year. For example: ...teenagers should wake up later ("Studies on Teens", 2017). If the source you're citing, however, is a book, a report, or a periodical, then its title must be italicized: ...that sort of medicine has no effect over depressed people (Medical Weekly, 2018).