The best explanation for the causes of the Slave Code of 1740 is:
The Slave Code of 1740 was caused by a large-scale, deadly slave rebellion in South Carolina, and growing fears of future revolts.
This law was enacted in the aftermath of the Stono Rebellion of 1739, where enslaved people in South Carolina rose up against their enslavers, leading to a violent conflict. The fears of further uprisings led to stricter regulations and controls over enslaved people, resulting in the establishment of the Slave Code.