(a) The board may determine conclusively by resolution whether the mortgage or encumbrance represents all or part of the cost of the acquired property and constitutes a purchase money lien on the property.
(b) The board may contract to use and pledge its revenue derived solely from the sale of water and services supplied through the acquired properties for the payment of a purchase money lien.
(c) The board also may use revenue from taxation or from the issuance and sale of bonds to pay all or part of the amount due under the encumbrance if a majority of the electors of the district voting at an election on this proposition approve its use.