In the Parable of the Persistent Widow (Luke 18:1-8), what is the primary attribute of God that Jesus is emphasizing through the unjust judge's eventual concession?

A God's reluctance to intervene in human affairs. B God's susceptibility to manipulation through relentless prayer. C God's inherent justice and willingness to answer persistent prayer, even when it seems delayed. D God's preference for the poor and marginalized over the wealthy and powerful.