Final answer:
The correct answer is option A button worn by store clerks that reminds shoppers to use reusable shopping bags.
Step-by-step explanation:
Feedback is a critical concept in biological systems, where it helps to maintain homeostasis. This response can be categorized as either positive feedback or negative feedback. Positive feedback amplifies changes and moves a system away from equilibrium, whereas negative feedback attenuates changes and maintains stability within a system. An example of positive feedback is the release of prolactin during breastfeeding, which increases milk production as the baby suckles more. On the other hand, the regulation of body temperature is an example of negative feedback, where sweating reduces body temperature when it becomes too high, ceasing once the temperature is normalized.
To illustrate the given examples, a sign at a stadium or a button worn by clerks provides a reminder and encourages a behaviour but does not actually respond to the behavior it instigates, nor does the reminder change based on the magnitude of the action taken by the person seeing it.
However, an orb that changes color based on the amount of energy consumed is providing direct feedback in response to energy usage—this kind of real-time data reflects negative feedback. Similarly, an energy use label doesn't provide feedback directly related to the ongoing use of an appliance and thus isn't an example of feedback in the biological sense.