None of the options are correct for me. Why would you divorce them when you were in on it the whole time? And on the other hand, why do you even need to forgive them when they lose? They are human, in fact when your partner loses what you should do is to go and console them. Make them understand that they may get it next time. And you should have told them from the onset to quit gambling or maybe play safe so they don’t lose everything instead of feeling offended when they finally do.
Probably the topic assumes that the gambler lose everything as in including the funds which they are both save. This is the common reason why married couple destroyed when the problem is due to gambling addiction.
Some people can’t stand already their partner once he already affected the family finances in general. No one will gonna have a problem if the gambler still earn or doesn’t loss since it’s still part of entertainment but I believe even can’t stand a husband/wife that spend too much in gambling to the point that your family savings is already at loss.