Which of the following statements is not correct regarding stock bonus plans?

a. Stock bonus plans allow for the current deductibility of non-cash contributions.

b. The required repurchase option for a stock bonus plan can create potential cash flow issues in the future.

c. Stock bonus plans are generally as cost efficient to operate as profit-sharing plans or money purchase pension plans.

d. The eligibility for a stock bonus plan could be age 20 and six months of service.