[PAULUS libro tertio quaestionum. ] §12.6.21.prPlane si duos reos non eiusdem pecuniae, sed alterius obligationis constitueris, ut puta Stichi aut Pamphili, et pariter duos datos, aut togam uel denaria mille, non idem dici poterit in repetitione ut partes repetant, quia nec soluere ab initio sic potuerunt.
[PAULUS, Questions, Book 3.] Clearly, if you establish two debtors, not for the same sum of money, but under an alternative obligation, as for example, for Stichus or Pamphilus, and both [slaves] are given at the same time, or [for an alternative obligation of] a toga or a thousand denarii [and both are given], the same cannot be said in respect of recovery, namely, that they should recover parts, because they could not have paid in this way from the beginning.
igitur hoc casu electio est creditoris, cui uelit soluere, ut alterius repetitio impediatur.
Therefore, in this case, the choice is the creditor's, to whom he wishes to restore, so that the recovery of the other is barred.