All of the following are required for a qualified employee stock purchase plan except: A. All eligible employees must be allowed to participate in the plan. B. An employee may not purchase more than $25,000 worth of stock (based on fair market value on the first day of the offering period) for each calendar year in which the offering period is in effect. C. Only employees of the company (or its parent or subsidiary corporations) may participate in the plan. D. Only employees owning more than 5 percent of the company stock may participate in the plan