The correct answer is C. humans
Language is an advanced system for communication available only to humans. Dolphins, chimps, and bees, use other means to communicate, but it is not a language, it's mostly things like smells or pheromones or similar things.
The oceans also regulate the global climate; they mediate temperature and drive the weather, determining rainfall, droughts, and floods. They are also the world's largest store of carbon, where an estimated 83% of the global carbon cycle is circulated
D. This has to be 20 characters long sooooo there
The dude on the top is right his answer is quite good!