The board may require separate capital budgets to give effect to a general improvement program as follows:
a. A special capital budget for the expenditure of funds realized from the sale of obligations and adopted at the time such sale is authorized.
b. A separate capital budget adopted at the same time and as part of the annual budget.
c. A consolidated capital budget providing for the consolidation of capital projects, with the annual budget treating borrowed funds and other receipts as special revenue and capital projects as separately itemized appropriations under the proper office, department, institutions or other agency of the local unit.
d. Any other type or form of budget adapted to planning and guiding expenditures for capital improvement programs.