A project's break-even occupancy level is determined by: _______________

a. adding vacancy and rent loss allowances to the net operating income, and dividing by the operating expenses.
b. subtracting debt service from the before-tax cash flow, and dividing by net operating income.
c. adding the operating expenses to the debt service, and dividing by the gross potential revenue.
d. subtracting operating expenses from effective gross income, and dividing by the operating expense ratio.