stimulus is a change in the environment that causes an organism to react. the response is the reaction to the stimulus. some examples of stimuli for zebras are drought, to many predators, and bad feeding grounds such as dead grass or plants. zebras respond to stimuli just like all other living organisms
what in the weirdo : o
i believe it's c. the trait for large beaks will be passed on to future generations through natural selection.
since eventually smaller beaks would have to find another source of food or even eventually just die out from the lack of food.