Final answer:
The true statement about respiratory gas exchange is that oxygen is released from the blood to the tissues, known as internal respiration, and occurs due to diffusion according to the concentration gradients.
Step-by-step explanation:
The correct statement regarding respiratory gas exchange is A. Oxygen is released from blood to tissues. This process, known as internal respiration, occurs when oxygen diffuses from the capillaries into the tissues. Meanwhile, carbon dioxide diffuses in the opposite direction, from the tissues into the blood. Moreover, external respiration occurs in the lungs' alveoli, where oxygen is picked up by the blood, and carbon dioxide is released. Gas exchange facilitates homeostasis by providing oxygen to cells and removing carbon dioxide waste.