In the Gospel of Luke, what is the primary theological significance of Jesus' parable of the Persistent Widow (Luke 18:1-8) beyond simply encouraging prayer?

A It primarily illustrates the importance of praying for material possessions. B It emphasizes God's willingness to grant immediate justice to all who ask. C It highlights the contrast between an unjust judge and a just God, promising ultimate vindication for the faithful in the face of adversity and delay. D It suggests that persistence in prayer can manipulate God into fulfilling our desires.