How does the parable of the Persistent Widow (Luke 18:1-8) contribute to our understanding of prayer beyond simply asking for our needs?

A It emphasizes the importance of praying loudly and publicly to gain God's attention. B It highlights the necessity of praying at specific times of the day for effective communication with God. C It illustrates the significance of unwavering faith and perseverance in prayer, even when answers are delayed, revealing God's justice and timing. D It suggests that prayer is only effective when we are in a state of constant suffering and need.