Under what circumstance can the trustee deviate from maintaining an impartial duty to beneficiaries?

The correct choice indicates that a trustee can deviate from their duty to maintain impartiality when the terms of the trust explicitly allow for such actions. Trust documents often contain specific provisions that outline how the trustee is expected to manage the assets and the distributions to the beneficiaries. If the language of the trust allows the trustee to exercise discretion in favor of one or more beneficiaries under certain circumstances, then the trustee is legally and ethically permitted to act according to those stipulations.

In contrast, options involving agreements among beneficiaries, perceived deservingness, or the profitability of the trust do not provide legally sufficient grounds for a trustee to act otherwise than impartially. While beneficiary consent may influence decisions, it does not override fiduciary duties unless granted authority in the trust document. Similarly, the idea of deservingness is subjective and goes against the duty of impartiality that trustees are required to uphold. Lastly, the lucrativeness of the trust does not inherently justify deviations from equitable treatment of the beneficiaries as dictated by the trust's terms. Thus, a clear and explicit provision in the trust agreement guiding the trustee’s actions is the foundation for any deviation from impartiality.