Answer:
Creon's new plan for Antigone's punishment includes the following: burying her alive, yet still providing her enough nutrition to keep her alive. The cause of this change of plan is because Creon knows that if he publicly stones Antigone he will lose the respect and loyalty of his subjects, and family, possibly resulting in a revolt against his reign.
I answered it on edge2020, and got it right. Hope it helps! :)