Please choose the correct ending to complete the given sentence: Pets and Animals: [header] How to train your rottweiler puppy with simple commands [title] Start early and short. [step] Puppies can be taught simple commands starting at seven to eight weeks of age. The key to training is to make each session fun and short.

Ending1: Though it may be tempting to get a puppy used to some of the new commands, try to limit the amount you use in the beginning. [substeps] Avoid starting your training sessions too early or your dog may feel it is not learning enough. Ending2: Start by giving your puppy a treat when you get your hands on it. You can name the target for the treat. Ending3: A minute or two for each month of age up to 6 months is a good ballpark figure. Trying to do more than that will not benefit you or the dog because his attention span can't handle it. Ending4: You can practice word or phrase commands, such as " sit " and " your ", or use a phrase that your dog can understand and learn from. [substeps] Using a long phrase like " sit " is a great way to build up your dogs' patience and familiarize them to certain commands.

Answer format: ending1/ending2/ending3/ending4