Please choose the correct ending to complete the given sentence: Pets and Animals: [header] How to change cat food [title] Pick cat food based on life stage. [step] The nutritional needs of your cat will change as they grow and age, so you should change their food when they are making a life transition. If your kitten is becoming a cat or your adult cat is becoming a senior, you should choose a food that is appropriate for their new stage of life.

Ending1: [substeps] Depending on their health and preferences, you may also want to switch between brands of cat food or between dry and wet varieties of food. [title] Mix the old with the new food. Ending2: If you are considering changing cat food for your senior cat, you should choose a food that is high in protein and low in fiber. High fiber cats have trouble digesting this content and eventually are unable to absorb the nutrients they need. Ending3: [substeps] Some brands of cat food are safer for kittens and provide more health benefits than others. [title] Provide enough food for your adult cat. Ending4: Most senior cats will reach a special age by this stage. [substeps] When a senior cat is older and in transition, it will need food with special nutrients.

Answer format: ending1/ending2/ending3/ending4