Answer: The statement that requires a citation when used in a research paper is A. Lorne Falconi suggests that an existential angst hovers over Salinger's characters.
Explanation: Citation is required when an author paraphrases or uses an idea that another author has already expressed in one of his/her texts. Statement A. is the one that requires citation as <u>it makes reference to an idea or interpretation about Salinger's characters that has been developed by another author </u>(<u>Lorne Falconi</u>). In other words, A. requires citation because it includes an idea that did not come out from the author's mind, but from another writer's mind.