Please choose the correct ending to complete the given sentence: Pets and Animals: [header] How to train your dog to not run away [title] Begin training a lot when your dog is still young. [step] Just like people, dogs tend to form lifelong behaviors when they're young. You may have a difficult time training a very young puppy, but it's always good to try.

Ending1: It may be frustrating if the puppy doesn't get used to going to the bathroom when he's old enough to, but he's willing to do anything for you as long as you give him the luxury. [substeps] Once he starts using the bathroom, put some leash or a towel in front of his bladder. Ending2: If you know you can train your dog soon, that's great. If you just know that your puppy wants to bark and to find a particular treat, here are some good starter tricks to practice as your dog ages : [substeps] If the puppy consistently attacks you, wait a few days for it to stop. Ending3: Let the older dog do the work or take the puppy out for playdates and treats. After your dog is 7 weeks old, your training sessions can still be fun. Ending4: If you've adopted an older dog, you can still retrain him or her, but it may prove more difficult. [title] Gather some special treats for your dog.

Answer format: ending1/ending2/ending3/ending4