"jill's husband slapped her because his laundry was not folded. jill feels guilty for not folding the laundry and will put forth extra effort to make sure this never happens again. what phase in the cycle of violence is this? "

I believe the answer is: Tension building
refers to situation where every little thing that we spot being done by the other party started to resulted in bigger conflict/confrontation.
Up to this point, one or both partners would start to develop some sort of deep resentment toward their partners.