What is NOT included as part of a cruise clearance?

The correct choice indicates that an authorization to descend under IFR conditions below minimum IFR altitude is not included as part of a cruise clearance. This is because a cruise clearance allows an aircraft to operate at a specific altitude but does not authorize descending below the established minimum IFR altitudes unless explicitly stated or cleared by air traffic control (ATC).

In IFR operations, each clearance comes with specific altitude constraints designed to ensure safety and separation from other aircraft. Therefore, maintaining altitude is an essential part of the clearance, as well as directives or guidelines relevant to safe departures and search-and-rescue provisions. However, descending below the minimum IFR altitude without an appropriate clearance would contravene safety regulations and could lead to potential hazards.