Please choose the correct ending to complete the given sentence: Pets and Animals: [header] How to train dogs not to bark [title] Do not reward the barking by shouting. [step] Training a dog not to bark early on is much easier than breaking the habit once your dog has developed it. One of the keys to this is to avoid ever reinforcing or rewarding barking in the first place.

Ending1: Simply shout a loud, startling bark and stop there. [substeps] Yelling either will not stop the barking, or it might even trigger other issues for your dog. Ending2: [substeps] Yelling is a much faster and more effective way to train a dog to silence its barking than scolding can be. Also, yelling is not to punish your dog for barking, as it might do more harm than good by more attention. Ending3: If your dog barks and you shout for quiet, you are rewarding the barking with attention in your dog's mind. Your dog may even interpret the shouting as your version of barking in response. Ending4: [substeps] Do not engage in this behavior early in the training process. Scream a high pitched voice at the top of your lungs for dogs to hear.

Answer format: ending1/ending2/ending3/ending4