premise: An author is planning to write a mystery novel consisting of seven chapters, chapter 1 through chapter 7. Each of seven different clues—R, S, T, U, W, X, and Z—is to be mentioned exactly once, one clue per chapter. The order in which the clues are mentioned is subject to the following constraints: T cannot be mentioned in chapter 1. T must be mentioned before W, and there must be exactly two chapters separating the mention of T from the mention of W. S and Z cannot be mentioned in adjacent chapters. W and X cannot be mentioned in adjacent chapters. U and X must be mentioned in adjacent chapters. Which one of the following could be true?
hypothesis: R is mentioned in chapter 7.