The prolonged increase in heart and breathing rates during the snow skiing trip was probably a result of: a. activation of the sympathetic autonomic nervous system by the new experience.
b. activation of the parasympathetic autonomic nervous system by the new experience.
c. hypoxia caused by insufficient blood hemoglobin concentration to supply oxygen for exercise at the low oxygen pressure found at high altitudes.
d. depressed core body temperature (hypothermia) caused by exposure to cold temperatures at high altitudes.