(N/A) Fig. $I$: It represents a single population where all individuals belong to the same species,i.e.,$A$. These individuals interact among themselves and with their environment,which is known as intraspecific interaction.
Fig. $II$: It represents a community containing three populations of species $A, B$ and $C$. These populations interact with each other and their environment,which is known as interspecific interaction.
Fig. $III$: It represents a biome. It consists of multiple communities (represented by the circles) that are in different stages of development or ecological succession. All these communities exist within the same environment and interact with each other and their surroundings.