Mater, a wealthy widow, wishing to make a substantial and potentially enduring gift to her beloved adult stepson Prodigal, established with Vault Savings and Loan Association a passbook savings account by an initial deposit of $10,000.For this question only, assume the following facts. The passbook was issued solely in Prodigal's name; but Mater retained possession of it and Prodigal was not then informed of the savings account. Subsequently, Mater became disgusted with Prodigal's behavior and decided to give the same savings account solely to her beloved adult daughter Distaff. As permitted by the rules of Vault Savings and Loan, Mater effected this change by agreement with Vault. This time she left possession of the passbook with Vault. Shortly thereafter, Prodigal learned of the original savings account in his name and the subsequent switch to Distaff's name. If Prodigal now sues Vault Savings and Loan for $10,000 plus accrued interest, will the action succeed?
Yes, because Prodigal was a third-party intended beneficiary of the original MaterVault deposit agreement.  Yes, because Prodigal was a constructive assignee of Mater's claim, as depositor, to the savings account.  No, because Prodigal never obtained possession of the passbook.  No, because Prodigal's right, if any, to the funds on deposit was effectively abrogated by the second Mater-Vault deposit agreement