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". 

[header] How to make black coffee [title] Purchase freshly roasted, whole bean coffee. [step] If you can't purchase it directly from the roaster within a week or so of it being roasted, opt for a vacuum-sealed bag from a reputable national coffee-bean roaster. [title] Purchase your own coffee grinder, or grind it in the store. <sep> (A) [step] If possible, choose a burr grinder in place of a normal blade grinder. For best results, grind the coffee fresh right before brewing each day. (B) [step] Grind coffee beans in the near-black zone of a coffee grinder. You can use either a regular-size grinder or a pre-grind grinder to grind your coffee. (C) [step] Modern coffee grinders have drawbacks, as they require higher temperatures to make purified coffee. Where possible, purchase one that comes pre-boil. (D) [step] Print it onto a piece of paper, remove the lid from the coffee grinder, and grind the coffee beans in the machine's center. [title] Unplug the coffee grinder and plug it into the wall outlet.
A

[header] How to train chickens to return to their coop [title] Prepare your chicken coop. [step] Before you can train your chickens to return to the coop in the evening, you need to ensure the coop is set up properly for your chickens. A basic chicken coop should provide at least twenty-four square feet of space and multiple places for chickens to perch. <sep> (A) To ensure proper lighting, you will need to buy a coop lamp or turn off the overhead light. You will also need to provide adequate heat. (B) Your chickens will probably also need a hutch, cart, or larder to keep them warm. All three features are important as you start building your chicken coop. (C) [substeps] Coop space should be compatible with how large or small your chickens may be. Don't space your chickens too close to each other. (D) [substeps] Make sure there is a plentiful supply of food and water inside the chicken coop. Wood beams mounted horizontally can provide good perching space for chickens.
D

[header] How to handle winter allergies [title] Minimize your exposure to dust and dust mites. [step] Dust and dust mites are common indoor allergens, so when winter comes (and you spend more time indoors) these allergy symptoms may worsen. The best way to combat the allergy symptoms is to prevent (or minimize) your exposure to the allergen in the first place. <sep> (A) [substeps] Limit exposure to dust products, pesticides, and other indoor allergens. Use windows that are cool and dry or places at least partially shaded. (B) [substeps] This is especially important if it is your first exposure to pollen and dust mites. Pollen mites can make you sneeze and cough, which may make you more susceptible to pollen mites. (C) Strategies to reduce the dust and dust mites in your home include : [substeps] Purchase a hepa air filter. This can help to clear dust out of the air, and hence reduce your allergy symptoms. (D) You can minimize your exposure to dust or dust mites by : [substeps] : blowing your nose, checking your closet, or looking out your windows. Keeping your windows clean and dry if possible.

C