Answer: Existence definition: The existence of something is the fact that it is present in the world as a real thing. Or The noun existence can be used many different ways, but it always has to do with being alive or with simply "being”.
Explanation:
Existence is the state of being alive or being real. For example, you and your best friend disagree about the existence of Bigfoot if you think it's real and your friend doesn't. Existence is the state of being alive or being real. For example, you and your best friend disagree about the existence of Bigfoot if you think it's real and your friend doesn't.
It's A. Primary succession :) because Human economics and ecology are linked together because human economics utilizes the ecosystem and the natural resources in older for economics to actually exist. :)))))))