Considering the cultural context of ancient Israel, what was the primary significance of the act of 'gleaning' left-over crops, as exemplified in the story of Ruth?

A It was primarily a means for landowners to dispose of unwanted crops efficiently. B It was a system designed to encourage hard work and self-reliance among the poor. C It was a legal and social provision rooted in the Law of Moses designed to provide sustenance and dignity for the poor, widows, and foreigners, reflecting God's compassion and justice. D It was a method to ensure that the land was thoroughly cleared after the harvest to prevent the spread of disease.