question_answer

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.

A)  B: red blood cell-transport of \[C{{O}_{2}}\]mainly

B)  C: arterial capillary - passes oxygen to tissues

C)  A: alveolar cavity - main site of exchange of respiratory gases

D)  D: Capillary wall - exchange of \[{{O}_{2}}\] and \[C{{O}_{2}}\]takes place here