What is the best response when a husband with dementia threatens divorce?

His anger usually only lasts one day because maybe he realizes the absurdity and he apologizes, but what is the best response in the moment to the situation? Ignore the untrue accusations and his feelings of anger and betrayal? Stand up to him? Deny everything that is untrue? Laugh at the absurdity? I know reasoning doesn’t work well, but some of it does sink in later.

Of course some of this depends on the person and the degree of memory loss. Mine has vascular dementia, and he has a lot of mental capacity still to remember things that happened earlier in the week, but not what the weather is like or things that happened 5 years ago. It seems like random memory loss.

What response have you found that works?