The correct answer is option B
The fishes that live in the shallow water along the sea floor needs a flattened shape and eyes on the dorsal side because they need to see above and have least possibility that the eyes will be required to see downwards as they lie at the sea floor.
They have tail for protection and flattened body for easy swimming.
Example: Stingray.
The exchange takes place in the millions of alveoli in the lungs and the capillaries that envelop them. inhaled oxygen moves from the alveoli to the blood in the capillaries, and carbon dioxide moves from the blood in the capillaries to the air in the alveoli.