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.
Example solution: Who believes Fagin's gang make wallets and handkerchiefs?.
Example explanation: 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.

Problem: Passage: Filmmaker Adam Green begins a documentary about artwork that features monsters.  Green is surprised when William Dekker, a retired police officer, contacts him and claims to have proof of the existence of monsters.  Green's wife reacts skeptically, but he reworks his documentary to focus on Dekker and his efforts to expose the monsters' underground home, which he calls "The Marrow". Green interviews Dekker at his house, who claims that he has seen many monsters and identified some of them through sketches. Dekker mentions his son once but diverts from the topic when Green inquires. The shooting crew of Green and his cameraman wait at the Marrow's entrance; a dug-up hole in the cemetery in the woods. On the first night they do not see anything although Dekker keeps claiming that he could see one of the monsters.
Solution: What is the full name of the person the police officer contact about monsters?