Please choose the correct ending to complete the given sentence: Pets and Animals: [header] How to prevent a dog from defecating in its crate [title] Make sure the crate is the right size. [step] Oftentimes, dogs will defecate in their crate if it's too big. If the crate is large enough that your dog can comfortably poop in a corner he might choose to go in his crate rather than wait to be let out.

Ending1: A small dog can poop in a small corner by himself to get away from crowding. [title] Prevent any urine from entering the crate. Ending2: [substeps] Your dog's crate should be just big enough for him to stand up and turn around in and lie down with his legs straight. Anything bigger might make him tempted to use the crate as a bathroom. Ending3: This way, most dogs can' move' inside the crate in order to poo. To prevent this from happening, make sure the crate is wide enough for the dog to be able to enter it without having to tip over. Ending4: [substeps] If this is the case, you should keep the crate door slightly ajar so that your dog will easily go out after he has peed or defecated on something. [title] Close the door when your dog is defecating.

Answer format: ending1/ending2/ending3/ending4