Final answer:
In biology, a response is an organism's reaction to changes in its internal or external environment, such as movement towards light or away from heat, and includes physiological reactions like sweating to cool the body.
Step-by-step explanation:
What is a Response?
A response in the context of biology is how an organism adjusts to changes in its internal or external environment. This can include movements, such as a plant turning its leaves toward the sun (phototropism), or the movement of unicellular organisms toward or away from chemicals (chemotaxis). It also encompasses more complex reactions in multicellular organisms, like humans responding to a hot surface by quickly withdrawing their hand. Additionally, organisms demonstrate responsiveness through physiological changes, like sweating and dilation of blood vessels to regulate body temperature when overheated.
Therefore, the correct answer to the student's question is C. how an organism answers to a change in its environment. This response to stimuli is a fundamental characteristic of life, enabling organisms to survive, reproduce, and maintain homeostasis.