Which of the following is used to prevent a bird from bating?

The correct choice, brail, is a key tool in falconry used to prevent a bird from bating, which is the act of flapping or trying to take off from a perch or handler. Brails are typically made from thin cords that are attached to the bird's wings and secured to the body of the bird or elsewhere to limit its wing movement. By doing so, they help keep the bird calm and steady, ensuring it stays in place instead of attempting to fly away.

Using brails can assist in the training process, allowing a falconer to manage the bird more effectively during handling or transporting. Other equipment, while essential in falconry, serves different purposes such as providing perches or securing the bird's feet but does not specifically address the behavior of bating like brails do.