The ultimate failure of the war on drugs and the three strikes law can be best summarized by option:
a) The prison population increased four-fold
This reflects the significant increase in incarceration rates as a result of harsh drug laws and mandatory sentencing, which has led to criticisms about effectiveness and disproportionate impacts on certain communities. While options b, c, and d highlight issues related to drug policy and law enforcement, the massive increase in prison populations is often viewed as a primary indicator of the overall failure of these policies.