Final answer:
Dr. Kerr asserts that when humans are scared, their bodies react with an increased heart rate and an adrenaline release as part of the fight-or-flight response.
Step-by-step explanation:
According to Dr. Kerr, our bodies respond to things that scare us with an increased heart rate and adrenaline release. This response is part of the "fight-or-flight" mechanism that occurs when we perceive a threat. The sympathetic nervous system triggers the release of adrenaline, leading to an accelerated heart rate and respiration.
In addition, the hypothalamic-pituitary-adrenal (HPA) axis becomes active, with the hypothalamus releasing corticotropin-releasing factor which causes the pituitary gland to release adrenocorticotropic hormone (ACTH). ACTH then stimulates the adrenal glands to secrete cortisol and adrenaline, priming the body for a fight or flight scenario. Therefore, the correct answer to the question is A) Increased heart rate and adrenaline release.