Please choose the correct ending to complete the given sentence: Work World: [header] How to build an indoor dog kennel [title] Choose a space for your kennel. [step] It is very important to choose the right place for an indoor kennel. The area must be warm, spacious, and comfortable.

Ending1: It must also be about 40 percent cooler. [substeps] Choose a location with good air flow and ventilation. Ending2: Ideally, you will want somewhere that receives at least eight hours of sunlight in a 3-20 ° f (13-27 ° c) range. This will create for optimal warm conditions for your dog. Ending3: Your kennel should not be crowded, since dogs can easily escape if they feel trapped in a confined space. Plus, make sure that you have adequate supervision. Ending4: It should be a safe environment for your animals. Consider these criteria : [substeps] The area should be spacious enough.

Answer format: ending1/ending2/ending3/ending4