The correct answer is A. On a separate page at the end of the document
Explanation:
APA Style guide is a manual that establishes the parameters for the publication of documents, in this way APA set rules for presenting different documents and includes guidelines for citations, headings, the format for pages, among others. In the case of citations APA includes guidelines depending on the type of citations used during the texts, additionally to this all sources cited in the text need to be listed on a separated page at the end of the document and should include at least the name of the author, the date of publication and the title, however, specific guidelines are set depending on the type of document. In this way, according to APA Style guide all works cited should be included in an alphabetical list at the end of the document, on a separated page and include the information about each source used in the document.