Final answer:
The enslaved were banned from being literate as a form of cultural suppression.
Step-by-step explanation:
The third reason why the enslaved were banned from being literate was Cultural suppression. Slave owners realized that education and literacy could empower enslaved individuals and potentially lead to uprisings or escapes. By suppressing their ability to read and write, slave owners could maintain control and reinforce the belief that slaves were inferior and incapable of intellectual pursuits.