In Sophocles' Antigone, why does Creon have Antigone locked "In a vault of stone" with a supply of food rather than having publicly executed as his own law demands?

AHe knows that the gods will execute her.

BHe is afraid to take responsibility for her death.

CHe is not sure that she is guilty.

DHe does not know that his son loves her.

Verified Answer :

I think the correct answer is B, simple because the other answer do not fit. 
A isn't correct because he doesn't care for gods' laws, since he decided to defy them by not allowing Antigone's brother to have a proper burial.
C isn't correct because he knows she is guilty, and she admitted to committing the crime.
And D is also incorrect, because his son was Antigone's fiance, so he must have known that his son loved her.