What is the name for a complex, organized group of organisms

Community

Explanation:

A community refers to a group of organisms including plants, animals and microorganisms, living and breeding together in a given area.

It is organized because some organisms called producers (plants) produce the food which is eaten by consumers (animals), and after the consumers die, Decomposers (microorganisms) feed on them.

Thus, community is the answer

not too sure but maybe in the hot springs.

a and c are the answeres