The Average Maturity of the Liabilities of an FI's Balance

The average maturity of the liabilities of an FI's balance sheet is equal to

A) the weighted-average of the liabilities where the weights are determined relative to the total liabilities and equity of the FI.
B) the weighted-average of the liabilities where the weights are determined relative to the total liabilities of the FI.
C) the weighted-average of the liabilities where the weights are determined relative to the total assets of the FI.
D) the weighted-average of the liabilities where the weights are determined using market values of liabilities.
E) None of these.