The graph below represents output from a model that simulates disease dynamics in a population. It is called a SIR model because it tracks the number of $($S$)$usceptible$,($I$)$nfected$,$ and $($R$)$ecovered individuals in the population. Using full sentences, identify what part of the population $(S,$I, and $R)$ each curve $($A$-$C$)$ represents. Please start a new line for each answer and label $"$A$","$B$"$ or $"$C$"$