Please choose the correct ending to complete the given sentence: Computers and Electronics: [header] How to calm an aggressive dog [title] Exercise your dog [step] . Many dogs that demonstrate aggressive behavior benefit from extensive exercise regimens. The more energy your dog burns the better their state of mind and the less likely they are to exhibit aggression.

Ending1: [substeps] Try either taking your dog for a walk in your backyard or taking it for a run. Choose a walking regimen when you train your dog. Ending2: [substeps] Take your dog for regular daily walks at least twice a day. Take your dog to the park to let them burn off excess energy. Ending3: These dogs also benefit from vigorous, frequent exercise. [substeps] Wear good posture and try not to tense your body up when exercising your dog. Ending4: [title] Play soon, feed your dog treats. [step] The simple act of playing with your dog is sure to relax their muscles.

Answer format: ending1/ending2/ending3/ending4