Respiration in insects Is called direct because

Options

A. The tissues exchange `O_(2)//CO_(2)` directly with the air in the tubes
B. The tissues exchange `O_(2)//CO_(2)` directly with the coelomic fluid
C. The tissues exchange `O_(2)//CO_(2)` directly with the air outside through body surface
D. Tracheal tube exchange `O_(2)//CO_(2)` directly with the hemocoel which then exchanges with tissues

Answer

D

Explanation

Direct respiration is the exchange of gases without any special respiratory organ and blood. In insect the tracheal tubes exchange `O_(2)` and `O_(2)` directly with the hemocoel which then exchanges them with tissues.