Please choose the correct ending to complete the given sentence: Computers and Electronics: [header] How to teach your dog " on by " [title] Invest in the right gear. [step] Buy a head or body harness for your dog that will allow you to direct the motion of their body. This will give you more control over the walking process.

Ending1: [substeps] The head harness works by joining the nose strap and securing the collar to the dog. The collar covers the muzzle and attaches both to the head and body harness. Ending2: The harness should fit snugly, but not tight enough to chaff the skin and cause irritation. Attach a thick, sturdy leash directly onto the harness and you are good to go. Ending3: In addition, it will increase its ability to carry its weight forward and out. [substeps] Try a neck halter, ankle or bun harness. Ending4: You should also consider purchasing a " lap harness "-type strap. These types of straps have been shown to help dogs with spinal or spine problems walk in a higher position.

Answer format: ending1/ending2/ending3/ending4