When do birds use their teeth

Explanation:

According to The Cornell Lab, "Birds do not have teeth, however, they may have ridges on their bills that help them grip food, but this does not count as teeth. So what about birds that have “tooth” in their name, like Double-toothed Kite? Some birds of prey have a sharp ridge or “tomial tooth” on the bill that they use to bite into their prey when subduing it. But these modifications to the bill surface are not considered the same thing as individualized teeth seen in other animals."

Hope this helps! <3

i think it would be b. tissue because an organ system is a group of organs that work together to perform one or more functions. each does a particular job in the body, and is made up of certain tissues.