David is researching caribou for a science project and learns they require

deep frozen ice to walk on while searching for food to survive. Which two

Earth systems are involved in the interaction of caribou and ice?

Answer: C. Cyrosphere and biosphere

Explanation:

Caribou are members of the Earth's Biosphere which is an umbrella term for all living organisms on Earth.

The Cyrosphere refers to any and all areas of Earth where water is in frozen form.

David learning that Caribou need deep frozen ice to walk on is therefore an interaction of these two systems as it shows a living organism being the Caribou interacting with deep frozen ice which is part of the Cyrosphere.