Which term refers to the official chosen for presidential succession in the event the President cannot serve?

The correct answer is the term referring to the official chosen for presidential succession in the event the President cannot serve is "designated survivor." This term specifically applies to a situation where, during events such as a State of the Union address or a similar gathering, one member of the Cabinet is chosen to remain at a secure location to ensure continuity of government in case of a catastrophic event that incapacitates the President and other high-ranking officials.

The designated survivor is part of a broader safety protocol in the U.S. government that ensures there is always an official who can assume the presidency. The choice of a designated survivor reflects the importance of maintaining a line of succession that is not interrupted by unforeseen circumstances, thereby safeguarding national governance.

Other terms mentioned, such as a Cabinet member, acting President, and Vice President, represent different roles in the government but do not specifically refer to the individual chosen solely for succession in the described context. The Vice President does have a defined role in succession and is next in line after the President, but the concept of a designated survivor is unique in its application to secure continuity in extreme situations.