Please choose the correct ending to complete the given sentence: Pets and Animals: [header] How to train an outdoor cat to use a litter box [title] Get an open litter box instead of a closed one. [step] A closed liter box may look nicer and be better at keeping the smells in, but an outdoor cat may not like it. Outdoor cats are used to the open, and a covered box may make them feel closed-in.

Ending1: This will result in your cat scratching so often, they may benefit from an inside litter box. [substeps] Some good places to get an open litter box are the cat park, pet supply store, or cat's perch. Ending2: Buy a window-sized litter box with a sliding lid or maybe even cover the top with a rubber mat. [title] Use noise-proof litter box if the cat isn't used to it. Ending3: [title] Make sure that the box is big enough. [step] The box needs to be large enough for the cat to be able to move around in. Ending4: A closed liter box is recommended by most indoor cats, who spend more time inside than outside. [substeps] Because you're shifting the litter box to a hidden location, you may want to keep a zippered box out of the way.

Answer format: ending1/ending2/ending3/ending4