(a) For purposes of this Code section, a beneficiary who is capable of expressing a choice is one:

(1) Who has a present interest, including but not limited to a vested remainder interest but not including trust beneficiaries where there is a trustee; and

(2) Whose identity and whereabouts are known or may be determined by reasonable diligence.

(b) An administrator with the will annexed may be unanimously selected by the beneficiaries of the will who are capable of expressing a choice unless the sole beneficiary is the decedent's surviving spouse and an action for divorce or separate maintenance was pending between the decedent and the surviving spouse at the time of death. When no such unanimous selection is made, the probate court shall make the appointment that will best serve the interests of the estate, considering the following preferences:

(1) Any beneficiary or the trustee of any trust that is a beneficiary under the will; or

(2) Those persons listed in paragraphs (3) through (5) of Code Section 53-6-20.

(c) For purposes of this Code section, a beneficiary's choice is expressed by:

(1) That beneficiary, if sui juris;

(2) That beneficiary's guardian or, if none, the person having custody of the beneficiary if the beneficiary is not sui juris;

(3) The trustee of a trust that is a beneficiary under the will; or

(4) The personal representative of a deceased beneficiary receiving a present interest under the will.