Final answer:
C.Stress is the physiological and psychological response to threats that require adaptation or adjustment, and it is designed to enable survival but can have negative health consequences if persistent.
Step-by-step explanation:
The physiological and psychological response to a condition that threatens or challenges a person, requiring adaptation or adjustment, defines stress. Stress provokes a series of complex physiological and behavioral responses known as the stress response, which can be conceptually viewed as fight, flight, freeze or fawn response.
This response is designed to help an organism survive by promoting adjustments in various systems, such as the cardiovascular, musculoskeletal, endocrine, and immune systems, to handle threatening events. However, unlike the immediate, adaptive responses of our ancestors to physical threats, modern threats are often psychological and can lead to negative health consequences if the response is chronic, such as increased susceptibility to heart disease and impaired immune function.