In which of the following cases should Frank, the executor of his father's estate, waive his executor's fee?'

I. Frank is a 35% taxpayer and his father's estate is beneath the applicable exemption amount.

II. Frank is the only heir of his father's estate, which is valued at $5,000,000.

III. The primary beneficiary of the estate is Frank's son, who is struggling to afford medical school; Frank is wealthy.

I only

II only

III only

I and III only

All of the above.