Which of the following is not a duty of a trustee upon termination of an account?

The correct answer revolves around the responsibilities of a trustee upon termination of an account. A trustee's duties at the time of termination include ensuring that all aspects related to the distribution of assets are handled properly, which encompasses confirming the distribution provisions stated in the governing instrument, assessing any tax liabilities related to the account, and determining the fair market value of all assets to facilitate accurate and equitable distribution.

Determining whether there is a co-fiduciary appointed is not part of the trustee's duties upon the termination of an account. This aspect is typically addressed prior to or during the ongoing management of the trust rather than during its winding up. The primary focus at termination is to finalize distributions and ensure compliance with legal and financial obligations, rather than revisiting co-fiduciary appointments. This makes it clear why the determination of co-fiduciaries does not fall under the specific set of responsibilities of the trustee at that final stage.