Which of the following is NOT an exception to the rule that there is no affirmative duty to act?

The correct choice identifies a situation that does not typically impose an affirmative duty to act on a defendant. In tort law, there are established exceptions to the general rule that individuals do not have a duty to intervene or assist others in peril. These exceptions include scenarios where a special relationship exists, such as between a guardian and a ward, the presence of peril due to the defendant's actions, and when a defendant has voluntarily assumed a duty of care.

In the context of public officials, while they may have certain duties inherent to their roles, there is generally no obligation imposed on them to take action in all circumstances simply by virtue of their public status. Therefore, merely being a public official does not create an affirmative duty to act to prevent harm or assist in emergencies. This lack of an automatic duty is what makes this choice stand out as not being an exception to the general rule governing affirmative duties.