Which of the following statements regarding stock options is true? Unexercised stock options that have been issued by an employer to an employee may be sold or transferred in the open market. O Employees earn stock options over the vesting period, which is usually contingent on the employee remaining with the employer for the entire vesting period O An employee will exercise a stock option only when the market price of the stock on the exercise date is less than the option price. O Companies expense stock-based compensation based on the fair market value of the stock on the expected date of exercise