Answer:
The correct option is B) a mushroom appearing wet in the rain.
Explanation:
A response is generated when a living body detects a change or event as a signal or a stimulus.
In the option A, the Sun acts as a stimulus. The response is the tree turning its leaves.
In the option C, touch is the stimulus. The contraction of the protozoa is the response.
In the option D, the smell of food is the stimulus. Rumbling of the stomach is the response.
In the Option B, no response is carried out by the mushroom. Hence option B does not show an action or response.
