How does the concept of 'koinonia' (fellowship) in the early church, as described in Acts 2:42, challenge modern individualistic interpretations of faith and discipleship?

A It suggests that individual spiritual growth is paramount and community involvement is secondary. B It primarily emphasizes financial contributions to support church leadership. C It highlights the interconnectedness of believers, emphasizing shared life, resources, and mutual responsibility within the body of Christ. D It promotes a hierarchical structure where only designated leaders are responsible for the spiritual well-being of the community.