I believe the answer is B: Earth's oceans absorb some of the carbon dioxide from the atmosphere.
The answer is the nervous system.
Hope this helps!
The spinal cord and the brain make up the central nervous system, and spinal cord nerves carry most messages between the brain and the rest of the body.
The vagus nerve carries the signal from the brain to the heart.
Frogs do have lungs but they are small and rarely used, frogs mostly take in moisture through the skin in process called cutaneous gas exchange.
