Answer: D, E

Characteristics of stock options: ① Stock options are rights rather than obligations. ② This kind of right is "gifted" by the company for free, which is essentially the "exercise price" of the stock option. ③Stocks cannot be obtained for free, and the "exercise price" must be paid. ④ Options are an uncertain expected income for operators. This income is realized in the market. The enterprise has no cash expenditure, which is conducive to reducing the incentive cost of the enterprise. ⑤ Achieving a high degree of consistency in the interests of operators and investors.