Final answer:
California reformed its three-strikes law due to prison overcrowding and financial strains, a shift in public opinion, and concerns over cruel and unusual punishment, aligning with the Eighth Amendment.
Step-by-step explanation:
California ultimately reformed its three-strikes law primarily due to the consequences of overcrowding in prisons and the accompanying financial burdens. This policy, which mandated life sentences for third-time felony offenders, even for nonviolent crimes, significantly contributed to the state's prison population growth. The reform of the three-strikes law was also influenced by a shift in public opinion, which began to question the effectiveness and fairness of such stringent measures, particularly for nonviolent offenses. Additionally, there was a growing awareness and concern over cruel and unusual punishment, with debates on the constitutionality of such harsh sentencing practices echoing the Eighth Amendment's prohibition against such penalties. Hence, among the options provided, California reformed the three-strikes law due to the overcrowding in prisons (C) and associated issues.