Your answer will be A producer because producers are plants they give off food and a lot of animals eat their their at the bottom of the pyramid because that have nothing in defense also an ts not D because those are like lions, and bears stuff that eat things (like predators) also its not B because omnivores eat both plants and animals like bears and when it came down to rather A, or C I choose A because herbivores are animals that eat plants like a sloth.
Your answer is A.
60 years is three half life for the substance, so 40*1/2^3=5
They differ from each other
Not completely sure, but maybe C.?
I would say A, B D are the correct answers