单选题 The owner of a firm gathers some information about her business. This year the firm's revenue is $300000. Cash expenses are $170000. Normal profit is $70000. Economic depreciation is $20000. If the owner could have earned $30000 per year in wages working for another company, the firm's economic profit is closest to:
A. $10000
B. $30000
C. $60000

【正确答案】 A

【答案解析】[解析] 经济利润(economic profit)等于总收入减去显性成本和隐性成本，现金费用是显性成本，正常利润、经济折旧和放弃的收入等属于隐性成本。300000-170000-70000-20000-30000=10000(美元)。