Considering the socio-political context of the divided kingdom, what was the primary theological significance of the prophet Amos's condemnation of Israel's social injustices?

A To promote military alliances with neighboring nations against Assyria. B To emphasize the importance of elaborate temple rituals over ethical behavior and treatment of the vulnerable. C To highlight the superficiality of their religious practices, demonstrating that true worship requires justice, righteousness, and compassion for the poor and oppressed. D To advocate for the abolishment of the monarchy and the establishment of a theocratic government.