Layers Through Which Gases Must Diffuse in External Respiration Include

Multiple Choice

Layers through which gases must diffuse in external respiration include those listed below.What is the correct sequence of these layers for oxygen diffusion in external respiration?
1) basement membrane of capillary epithelium
2) epithelium of alveolar wall
3) interstitial space
4) thin layer of fluid lining the alveolus
5) basement membrane of alveolar epithelium
6) epithelium of capillary wall

A) 2, 5, 4, 3, 1, 6
B) 5, 2, 4, 3, 6, 1
C) 6, 1, 3, 5, 2, 1
D) 4, 2, 5, 3, 1, 6
E) 6, 1, 3, 4, 2, 5