Answer:
A & C
Explanation:
Primary producers are always at the bottom of the food chain because they are the entry point of energy into the ecosystem. The producers are organisms that produce their own 'food' from abiotic factors and include photoautotrophs and chemoautotrophs. These organisms are then consumed by primary consumers who are subsequently consumed by secondary consumers who are subsequently consumed by tertiary consumers to decomposers. The number of consumers up the food chains can vary with ecososyems and can be an indication of how biodiverse they are. This is how energy and matter are passed up an ecosystem and recycled.
It would be a body fossil
