Final answer:
The main drawback of a nondurable power of attorney is that it ceases to be effective when the principal becomes incapacitated, which limits its usefulness in critical times when the principal cannot make decisions.
Step-by-step explanation:
The drawback of using a nondurable power of attorney is A) It ceases when the principal becomes incapacitated. This means that the power granted to the attorney-in-fact to make decisions on behalf of the principal ends if the principal can no longer make their own decisions due to mental or physical incapacity.
This is a significant limitation because it is precisely during times of incapacity that one would require the power of attorney to be most effective. By contrast, a durable power of attorney remains in effect even after the principal’s incapacity, providing uninterrupted authority to the attorney-in-fact to manage the principal's affairs.