Physiological Stress is defined as:

• A. The body's chemical reactions to the demands placed on it.
• B. Mental stress resulting from difficult work or personal situations.
• C. The energy reserve available for flight.
• D. The gap between your abilities and the task requirements.

Answer: (A)

Physiological stress is the body's chemical response to demands placed on it. When a stressor is encountered, the sympathetic nervous system and the hypothalamic–pituitary–adrenal axis release hormones such as adrenaline and cortisol. This chemical cascade prepares the body for quick action: heart rate and breathing increase, blood flow shifts to muscles, pupils dilate, and glucose is released for immediate energy. In flight, physical demands like turbulence, time pressure, long missions, or vibrations can trigger this response, which can influence performance if not managed. This is different from mental stress, which is about perceived strain or worry; it’s also different from energy reserves (the fuels stored for use) or from a mismatch between what you can do and what a task requires.