The answer to ur question is A
Heat and light (campfire), chemical ( beans as food), and kinetic (you hiking).
The correct answer is HPA axis.
The Hypothalamic-Pituitary-Adrenal (HPA) axis is one of the most important neuroendocrine systems, which regulates the stress response and other functions such as the digestion, mood, emotions and the immune system.
The hypothalamus, when triggered by a possible stressor, releases two hormones; the vasopressin and the corticotropin-releasing hormone (CRH). CRH, in turn, triggers the release of the adrenocorticotropin hormone (ACTH) from the pituitary gland. As a result of the secretion of ACTH, cortisol is secreted by the adrenal cortex.
Cortisol is a steroid hormone, considered to be our body's stress hormone.
Simple handwashing is more than enough to stop the spread of infectious diseases. The hands play a major role in spreading pathogens because it can come into contact with infected surfaces. Make sure to wash your hands especially when they get soiled or before you eat or drink.