Considering the parable of the Persistent Widow (Luke 18:1-8), what does Jesus emphasize about God's character in relation to prayer and justice?

A God is reluctant to answer prayers and must be worn down by persistence. B God is unjust and favors those who are persistent, regardless of their worthiness. C God is apathetic to human suffering and only responds to those who relentlessly demand His attention. D God, though not needing to be persuaded like an unjust judge, will certainly answer the persistent prayers of His people and bring about justice.