Please choose the correct ending to complete the given sentence: Pets and Animals: [header] How to shelter a horse [title] Build a three-sided shelter to protect your horse from the elements. [step] At a minimum, a horse should have access to a three-sided shelter with a waterproof roof. To provide maximum protection against drafts, place the structure against the prevailing winds in your area.

Ending1: [substeps] Ideally, the outline of the structure should be at least 20 feet (60 m) tall and attach three-sided walls: one door for the barn and one for the door to the barn. [title] Place the shelter in a location that is protected from the elements. Ending2: [substeps] For example, if winds typically blow from the north and west, position the shelter so the open side faces the southeast. The three-sided shed should be big enough to fully cover all the horses that you keep in your field. Ending3: Cover the structure with a tarp, so that the horse can't access the shelter. Keep the shelter sheltered for the day, and in the afternoon as well. Ending4: [substeps] If you don't have a shelter at all, you can store your horse inside one of many small tubs. You can also secure the top of one square-shaped cooler or one hot tub with seven foot blocks.

Answer format: ending1/ending2/ending3/ending4