Sun plankton sea bass otter plankton gets energy from the sun then the sea bass eats it to gains it energy and then the otter consumes the sea bass (fish)
plankton use photosynthesis to absorb energy from the sun to create food. sea bass consume plankton by filtering them from the water while otters will catch and eat the seabass
I would say C. Why I say this is because fur is used to keep an animal warm. If the animal no longer needs to be kept warm, then it no longer needs the thick fur.