The interest rate$($s$)$ used in computing avoidable interest is the: $$ lower of the rate incurred on specific borrowings or the weighted$-$average rate. $$ rate incurred on specific borrowings for the weighted$-$average expenditures equal to the specific borrowings and the weighted$-$average rate of other borrowings for the excess expenditures. O rate incurred on specific borrowings. O weighted$-$average rate incurred on all other outstanding debt.