CFRs apply to which of the following?

The correct answer is that the Code of Federal Regulations (CFRs) apply to all aircraft operating in the U.S., which includes both U.S. registered and foreign aircraft. This comprehensive applicability ensures that all aircraft, regardless of their country of registration, adhere to safety, operating, and regulatory standards established by the Federal Aviation Administration (FAA).

This approach promotes uniformity in aviation safety and operations within U.S. airspace. By encompassing foreign aircraft, the CFRs contribute to maintaining a consistent level of safety practices across all aircraft types, thus enhancing the overall safety of the National Airspace System (NAS).

The incorrect options focus on limitations based on registration status or type of operation, which would not align with the regulatory framework of the FAA that mandates safety regulations irrespective of an aircraft's country of origin or its operational nature.