In the parable of the Persistent Widow (Luke 18:1-8), what key theological point does Jesus emphasize through the contrast between the unjust judge and God?

A God, like the unjust judge, must be constantly harassed before he will answer prayers. B The parable primarily teaches the importance of relentless nagging to achieve desired outcomes. C Although God is just and responsive, effective prayer requires manipulative tactics. D Unlike the reluctant and uncaring judge, God is eager to answer the prayers of those who persevere in faith, implying his inherent goodness and willingness to help his children.