Final answer:
Nat Turner's Rebellion was the event that terrified Southern slave owners and eliminated the possibility of voluntary emancipation.
Step-by-step explanation:
The event that terrified Southern slave owners and eliminated the possibility of voluntary emancipation was Nat Turner's Rebellion.
Nat Turner's Rebellion was a slave revolt that took place in Virginia in 1831. Turner, an enslaved African American, led a group of slaves in a violent uprising against their owners. The rebellion resulted in the deaths of around 55 to 65 white individuals, including men, women, and children.
As a response to the rebellion, Southern slave owners tightened their control over enslaved individuals and imposed even stricter measures to prevent future rebellions. This event further reinforced the proslavery stance in the South and made voluntary emancipation less likely.