Answer:
A
Step-by-step explanation:
In order to maintain homeostatic balance in human, negative feedback loop and sometimes positive feedback loop are usually employed. The control mechanism consists of receptors and effectors (muscles and glands). The Receptors are sensory cells that acts like sensors to detect changes stimuli from the internal and external environments and relay these as input to the control center the brain. The brain processes the input and send the information as output to the effectors to bring about a corrective effects.
The control by the negative and positive loop are usually within the set-points so that the homeostatic balance of the body is maintained.
In this present scenario, the imbalance in body temperature (drop )is detected by the receptors in the skin (thermoreceptos, so named because they are sensitive to heat). They sent input as temperature fluctuations to the brain the control center.Analysis by the brain is relayed as output to the effectors (skeletal muscles) to contract, repeatedly. This is shivering. It is a thermogenic mechanism of increasing body temperature when it drops.
Therefore the skeletal muscles is the effector because , it causes a biological change(shivering) in the body reverse the rise in body temperature, and returns it to normal level.
The entire process is called thermogenesis. Once the temperature reached the set-point the thermoreceptors, sense this and send corrective input for the brain to stop the stimulation of the temperature control center : hypothalamus to reduce the output to the effectors Therefore, he skeletal muscles relaxed. and shivering is stopped
Although this is a corrective measure, it has disadvantage of withdrawing heat energy from the body core temperature via vasodilitation and loss to the surrounding environment via convention.