Someone drops a book on the floor, and it makes a loud noise. At that time, you turn to look at the person who dropped the book. The loud noise is an example of a… A. Hydrotropism

B. Stimulus

C. Response

D. Phototropism

Stimulus

Explanation: The definition of Stimulus is "a thing or event that evokes a specific functional reaction in an organ or tissue," according to the Oxford Dictionary. So the book dropping and causing a noise is an example of a stimulus.

i believe that it is a exoplanet

10 years is the answer