ESOPs and Stock Bonus Plans

Which of the following statements concerning the characteristics of ESOPs and stock bonus plans is correct?

1. The employer is required to make a specific annual contribution.
2. Non-vested account balances of terminated participants are usually reallocated to the remaining participants.
3. The employer assumes the risk associated with the investment of trust fund assets.
4. The increased investment diversification is an inherent benefit of such plans.