In this task, you are given a context and four options. Each option is a suggested ending for the context. You should read the context and pick the best ending for the context. Please answer with "A", "B", "C", and "D". 

Q: [header] How to clean a vornado fan [title] Clean out dust in the outer grills using a vacuum cleaner brush. [step] You can use a brush attachment on a vacuum cleaner to clean out all of the dust from the outer grills. Make sure the fan is unplugged before vacuuming. <sep> (A) [title] Place a cleaning rod in each section of the fan and squirt some cleaning fluid through each rod. [step] Avoid getting any grease in the vents or rest tray. (B) Some of the cleaner should be removed from the outside if you use a cloth and brush as cleaning instructions are laid out in the manual. [substeps] Avoid cleaning the outer grills with dust because it can detach some of the insulation and contribute to the fan's cooling. (C) Wipe down the inside of the cover every few minutes so you can put the fan back together. [substeps] For maximum efficiency, you should wash your vornado fan at least once a month, which is right after each dry run. (D) Go slowly when vacuuming to ensure you clean out as much dust as possible. [substeps] This will only clean the outer part of the fan, not the inside blades.

A: D
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Q: [header] How to cure swollen gums [title] Talk with your dentist. [step] Make an appointment with your dentist if you notice that your gums are bleeding or irritated throughout the day. You can also bring up this issue with your dentist when you see them every 6 months for a cleaning. <sep> (A) [substeps] You can also get a referral to a dietician who specializes in simply treating swollen gums at home. They may be able to diagnose swollen gums by looking at how your gums feel. (B) You can ask that your dentist discuss all of the possible treatment options with you. [substeps] Your dentist will likely order annual x-rays for you. (C) Dentist visits will help clear up any bleeding and ease your pain. [substeps] Some gums naturally bleed after eating. (D) You might end up visiting your dentist twice a year for repeated cleanings. [title] Avoid gum infections if you suffer from a periodontal disease.

A: B
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Q: [header] How to study for the mcat [title] Review the current year's mcat guide. [step] The mcat guide is published by the american association of medical colleges. Each year the aamc prepares a detailed description of the exam sections. <sep> (A) In addition, you can familiarize yourself with the english section and help you prepare for the exam. [substeps] Go to https: // aamc.org/docs/comprehensive/about/mcat/submitre/to keep up with the current year's information. (B) The mcat guide provides an outline of the exam sections and provides accurate charts and graphs to study for. [substeps] You can find a copy of the original guide for each school at https: // www.aamc.org/aamc.html. (C) [substeps] Mark the dates and locations on the guide. List the questions or tests for each exam. (D) Use this guide as a reference to guide your studies. [title] Prepare yourself for the length of the exam.

A:
D
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