Please choose the correct ending to complete the given sentence: Pets and Animals: [header] How to keep a whelping box clean [title] Line the bottom with vinyl flooring. [step] If you have built your own whelping box, you may have used wood or cardboard for the bottom. These materials are not easy to keep clean.

Ending1: As such, it is a good idea to line the bottom of your box with vinyl flooring. This can be purchased at any home improvement store, and is self-adhesive. Ending2: All of these materials may end up staining the vinyl surface, so make sure the bottom is very clean. [substeps] Mix 5 gallons (13 l) of very mild liquid dish soap with 2 gallons (3.78 l) of water. Ending3: When buying a whelping box, the first thing you should do is decide how large the box will need to be. If the box is going to be in the kitchen, then there is no need to make it too large. Ending4: Further, the vinyl floors may rot and cause damage to the whelping box, so never use plywood to cover the box. [title] Space your whelping box around the dog's natural habitat.

Answer format: ending1/ending2/ending3/ending4