Explanation
Correct answer: C.
Choice C is the best answer because as used in the text, “reserve” most nearly means constraint, or repression of one’s behavior or actions. The text indicates that although the narrator’s landlady is ordinarily “a store-house of innocuous anecdote” who readily produces “a volume of detail” in response to questions about her acquaintances—that is, she usually tells harmless stories and is willing to share details about people she knows—she is “unexpectedly reticent,” or surprisingly unwilling to speak, when it comes to Ethan Frome. The narrator then observes that the landlady doesn’t appear to disapprove of Ethan, she simply seems completely reluctant to speak of him. In this context, then, “reserve” refers to the landlady’s constraint—her repression of her usual willingness to share details in conversation.
Why the other choices are wrong
Choice A
Choice A is incorrect. “Modesty” can refer to being appropriate in speech or behavior, and one might consider it appropriate to decline to speak of someone, but the text gives no indication that the narrator thinks the landlady is acting out of modesty. The narrator suggests that the landlady generally isn’t concerned about the appropriateness of discussing others (she’s usually “a store-house of innocuous anecdote” and shares many details) and isn’t holding back to avoid saying something negative about Ethan Frome (there’s “no hint of disapproval”); indeed, the narrator suggests he can’t tell why the landlady is so unwilling to speak of Ethan.
Choice B
Choice B is incorrect because the text never suggests that the landlady has any “misgiving,” or feeling of doubt or apprehension, about Ethan Frome. In fact, the text explicitly states that there is “no hint of disapproval” in her surprising unwillingness to discuss Ethan.
Choice D
Choice D is incorrect because the narrator doesn’t suggest that the landlady is acting with “composure,” or calmness and control of her emotions. Instead of describing the landlady’s emotional state or presenting her as calm, the narrator simply conveys her surprising unwillingness to discuss Ethan Frome.