Which of mendel’s generations was allowed to self-pollinate?

Mendel allowed the F1 generation plants to self-pollinate

Explanation:

The parent plants in the tests carried by Mendel have recognized as the P (for parent) contemporaries. The F1 stands for the first filial generation, which was taken on cross-pollinating the parent plants. The F2 holds for the second generation, which is accomplished after self-pollinating the F1 breeding plants.

thinking it would be d not too sure but i think it's right

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