Over the past two years, a firm reported h
题型：单项选择题
问题：
Over the past two years, a firm reported higher operating cash flow as a result of securitizing its accounts receivable and from increasing income tax benefits from employee stock options. The tax benefits are solely the result of higher tax rates. Should an analyst conclude that these two sources of operating cash flow are sustainable（）
A. Neither source is sustainable.
B. Both sources are sustainable.
C. Only one of these sources is sustainable.