the average yearly rainfall in the ecosystem the types of producers found in the ecosystem the size of a predator population in the ecosystem the microorganisms living in the soil of the ecosystem
I gave my students this multiple choice question: Which of these is an abiotic element in an ecosystem?

Only one answer is correct among these 4 choices:
- the average yearly rainfall in the ecosystem
- the types of producers found in the ecosystem
- the size of a predator population in the ecosystem
- the microorganisms living in the soil of the ecosystem

Could you tell me which one is correct?

the average yearly rainfall in the ecosystem