If you choose this option, we will find which of these three options results in more household lifetime discretionary spending: 1) Withdrawing from Roth accounts first results, 2) non-Roth accounts first, or 3) smooth withdrawals to be taken from Roth accounts and Non-Roth accounts proportional to the total assets in both types of account. 

Note that in married/partnered families, if there is at least one Roth account and one non-Roth account held by either individual in the family then both individuals will have the option to optimize the order of Roth/non-Roth withdrawals. This is the case even if neither individual holds both types of accounts because retirement account assets can be inherited.