In Studies of Dogs Running on Treadmills,a Researcher Found That

In studies of dogs running on treadmills,a researcher found that when the dogs were running at 3 mph,the average value of CO₂ partial pressure was 39.0 mm Hg and the average respiratory minute volume in L/min was 9.0.The treadmill speed was then increased to 6 mph;the initial recordings are shown in the tables below.You can conclude from these data that when the dogs started running at twice the speed,their

A) arterial CO₂ partial pressure was relatively unchanged.
B) arterial CO₂ partial pressure increased exponentially by a power of 2.
C) respiratory rate increased.
D) respiratory rate was unchanged.
E) Both a and c