Explanation
Choice D is the best answer. The text introduces Earle’s prediction about something that she does not fully understand. It is characterized as an expectation. The word "anticipates," which means predicts, accurately reflects the uncertain but expectant nature of her claim.
Choice A: "contests" means challenges. The text does not suggest that Earle challenges this expectation.
Choice B: "denies" means rejects. This would not make sense in context, since the text claims that the hypothesis fuels her commitment to studying the subject.
Choice C: "substantiates" means proves. There is no mention in the text about her attempt to prove her expectation.
✨ Expert's Tip ✨
Identify the key parts that provide clues for the right word ("This expectation" and "... while she can't estimate … ").