The graph models core body temperature during a rapid change in environmental conditions. which statement explains the pattern in the graph?
a. body temperature varies in a predictable pattern during the day.
b. body temperature is controlled by an internal feedback mechanism.
c. vasodilation and vasoconstriction are dependent on the time of day.
d. vasodilation and vasoconstriction trigger an immediate increase in body temperature.

B. Body temperature is controlled by an internal feedback mechanism.

Explanation:

The monitoring of body homeostasis is mainly performed by the feedback mechanisms that keep homeostasis within a balance of antagonistic actions, ie, contrary. Body temperature, for example, is controlled by the feedback mechanism.

When a certain change occurs in the human body, the feedback mechanism can react in two ways: positive feedback and negative feedback.

Negative feedback acts to reverse the change that has occurred. Let's look at an example: When body temperature decreases due to cold, skin receptors send messages to the brain informing about the decrease in temperature. The brain, in turn, sends a response to the muscles to contract (tremor) and thereby generate heat. When body temperature returns to normal, the brain will transmit information to the muscles to stop the contractions. Therefore, on cold days, our body “shakes” and consequently generates heat.