Chapter 8, Problem 2RQ

In the healthy individual in the upright position, the

1. V/Q ratio is highest in the lower lung regions

2. ${\text{PA}}_{{\text{co}}_{\text{2}}}$ is lowest in the upper lung regions

3. V/Q ratio is lowest in the upper lung regions

4. ${\text{PA}}_{{\text{co}}_{\text{2}}}$ is highest in the lower lung regions

A. 1 only

B. 2 only

C. 4 only

D. 3 and 4 only