The figure given below shows a small part of human lung where exchange of gases takes place in which one of the options given below the one part A,B,C or D is correctly identified along with its function

Options

A. B: Red blood cell - transport of `CO_(2)` mainly.
B. C: Arterial capillary - passes oxygen to lt brgt tissues
C. A: Alveolar cavity - main site of exchange of
respiratory gases
D. D: Capillary wall - exchange of `O_(2)` and `CO_(2)`
takes place here

Answer

C