Within the Parable of the Persistent Widow (Luke 18:1-8), what aspect of God's character is Jesus primarily emphasizing through the contrast between the unjust judge and God?

A God's reluctance to answer prayers promptly, requiring believers to repeatedly petition Him. B The necessity of manipulative tactics in prayer to overcome God's perceived indifference. C God's inherent justice and willingness to respond to the cries of those who are oppressed and vulnerable, especially when they persevere in faith. D The importance of demonstrating unwavering faith through public displays of religious devotion.