Please choose the correct ending to complete the given sentence: Pets and Animals: [header] How to train a dog to stand up [title] Use a marker sound. [step] Marker sounds are sounds that please the dog and let it know it has done something right. The marker sound could be a word or a sound.

Ending1: The most common marker words are " yes! " or " good dog! " marker sounds are usually made by a clicker, a small hand-held device that helps in dog training. [substeps] You can obtain a clicker at most local pet stores. Ending2: A good method for making marker sounds is to have your dog stand with its shoulders back and its arms crossed. Your dog should keep its head up, with its eyes closed, not crossed. Ending3: After indicating the correct sound it can take your dog's attention and give it a look of confidence. This sound may be a word or phrase. Ending4: It could sound like " happy, " " bad, " or something similar. As soon as the dog notices the marker sound, say the word or the sound it makes, specifically in a voice that is such that the dog can hear.

Answer format: ending1/ending2/ending3/ending4