Answer:
Individual.
Step-by-step explanation:
The diagram is showing how the biosphere is composed of, ending at ecosystem. Within an ecosystem, there is a community. Within a community, there are different populations. In one population, there are individuals that make it up.
So, since individuals make up a population, populations making up a community, and communities making up ecosystems, you find your Q to be individual.
-------------------------------------------------------------------------------------------------------------
I hope this helps!
-No one