Considering the cultural context of the Old Testament, what was the primary significance of Boaz's actions in marrying Ruth, beyond simply providing her with security?

A To establish a political alliance with Moab, benefiting his family's social standing. B To fulfill the kinsman-redeemer obligation, ensuring the continuation of Elimelech's family line and inheritance. C To demonstrate his personal wealth and influence within the community of Bethlehem. D To challenge the existing social norms and advocate for the rights of foreign women.