Instructions: 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.
Input: Passage: The United States has lost the war on drugs. Substance D, a powerful and dangerous drug that causes bizarre hallucinations, has swept the country. Approximately 20% of the total population is addicted. In response, the government has developed an invasive, high-tech surveillance system and a network of undercover officers and informants.
Bob Arctor is one of these undercover agents, assigned to immerse himself in the drug's underworld and infiltrate the supply chain. Sometime in the past, Arctor abandoned his wife and two children, leaving him alone in a now-rundown suburban house in Anaheim, California; the house has since been repopulated by Arctor's two drug-addicted, layabout housemates: Luckman and Barris. The three spend their days intoxicated and having long, paranoiac conversations. At the police station, Arctor maintains privacy by wearing a "scramble suit" that constantly changes every aspect of his appearance and he is known only by the code name "Fred." Arctor's senior officer, "Hank", and all other undercover officers, also wear scramble suits, protecting their identities even from each other.
Since going undercover, Arctor himself has become addicted to Substance D and has befriended the main woman he has been spying on: a cocaine addict and Substance D supplier named Donna. Arctor hopes to purchase large enough quantities of Substance D from Donna so that she is forced to introduce him to her own supplier, but he has also developed seemingly unrequited romantic feelings towards her.
Output:
What drug is Arctor's love interest hooked on?