Today's Prison Population Being Larger and More Diverse Than It

Today's prison population being larger and more diverse than it was in the past is due to what?

A) the incarceration of many property and drug offenders who previously were not sentenced to prison
B) the larger proportion of offenders being white
C) the prison population becoming "middle crime age" (age twenty-five to thirty-five) and physically and emotionally unhealthy
D) the decreasing percentage of elderly offenders