141. During a study of exercise physiology, a healthy 30-year-old woman runs on a treadmill for 20 minutes at a rate of 7 miles per hour. At the end of the study, her cardiac output has increased from 5 L/min to 15 L/min; the cerebral perfusion pressure has remained relatively constant. Which of the following mechanisms best explains these findings? A) Decreased intracranial pressure B) Increased cerebrospinal fluid reabsorption C) Increased venous drainage D) Myogenic arteriolar constriction E) Reflex bradycardia K

141. During a study of exercise physiology, a healthy 30-year-old woman runs on a treadmill for 20 minutes at a rate of 7 miles per hour. At the end of the study, her cardiac output has increased from 5 L/min to 15 L/min; the cerebral perfusion pressure has remained relatively constant. Which of the following mechanisms best explains these findings? A) Decreased intracranial pressure B) Increased cerebrospinal fluid reabsorption C) Increased venous drainage D) Myogenic arteriolar constriction E) Reflex bradycardia K