Given the task definition, example input & output, solve the new input case.
In this task, you're given passages that contain mentions of names of people, places, or things. Some of these mentions refer to the same person, place, or thing. Your job is to write questions that evaluate one's understanding of such references. Good questions are expected to link pronouns (she, her, him, his, their, etc.) or other mentions to people, places, or things to which they may refer. Do not ask questions that can be answered correctly without understanding the paragraph or having multiple answers. Avoid questions that do not link phrases referring to the same entity. For each of your questions, the answer should be one or more phrases in the paragraph, and it should be unambiguous.
Example: Passage: Nearing London, Oliver encounters Jack Dawkins, a pickpocket more commonly known by the nickname the "Artful Dodger", and his sidekick, a boy of a humorous nature named Charley Bates, but Oliver's innocent and trusting nature fails to see any dishonesty in their actions. The Dodger provides Oliver with a free meal and tells him of a gentleman in London who will "give him lodgings for nothing, and never ask for change". Grateful for the unexpected assistance, Oliver follows the Dodger to the "old gentleman's" residence. In this way Oliver unwittingly falls in with an infamous Jewish criminal known as Fagin, the gentleman of whom the Artful Dodger spoke. Ensnared, Oliver lives with Fagin and his gang of juvenile pickpockets in their lair at Saffron Hill for some time, unaware of their criminal occupations. He believes they make wallets and handkerchiefs.
Output: Who believes Fagin's gang make wallets and handkerchiefs?.
This question is based on the following sentence in the passage "He believes they make wallets and handkerchiefs". It evaluates the understanding that the pronoun "he" refers to name "Oliver". You can ask questions like this one about most pronouns in a paragraph.

New input case for you: Passage: Sister Mary Bonaventure is in charge of the hospital ward of a convent in the county of Norfolk, England. She is troubled by her own sister's suicide, which she confides to her Mother Superior.
A torrential rain closes nearby roads, causing Sergeant Melling of the police to bring condemned murderer Valerie Carns there. She is being taken to prison.
Valerie was convicted of poisoning her brother Jason, a pianist. Jason's physician, Dr. Jeffreys, is head of the hospital where Sister Mary now works. Valerie still proclaims her innocence, but Jeffreys insists that she gave Jason a fatal overdose of his medicine.
A photograph of Jason clearly disturbs Isabel Jeffreys, the doctor's wife. He gives her a sedative. Valerie appeals to Sister Mary to bring her fiance, Sidney Kingham, to the convent to see her. A servant tells Sister Mary about the sadistic behavior of Jason Carns and produces a love letter to him, clearly written by Isabel.
Mother Superior is upset by Sister Mary's meddling. She burns the letter. The nun still intends to tell Melling the police sergeant what she knows.
Dr. Jeffreys is the one who gave Jason the fatal dose, and he might be slowly poisoning Isabel as well. He lures Sister Mary to a bell tower, where he attacks her. She rings the bell. Sidney hears it, rushes to her aid and overpowers Jeffreys, who is arrested by Melling.
Sister Mary's faith is restored, believing the rain that delivered Valerie to her to be divine intervention.
Output:
Who did Dr. Jefferys give a fatal dose of poison to?