Which of the following statements is true regarding the shipping of nuclear gauges by air?

Nuclear gauges contain radioactive materials, and their shipping is subject to strict regulations to ensure safety and compliance with international guidelines. The correct answer reflects the fact that nuclear gauges can only be transported on cargo aircraft. This regulation is in place because cargo aircraft operators are equipped to handle hazardous materials, including those that are radioactive, and they follow stringent protocols to mitigate risks associated with their transport.

Shipping nuclear gauges on passenger aircraft is prohibited due to the higher safety risks involved with mixing radioactive materials and the general public, as passenger aircraft are not designed to handle such dangerous goods. Additionally, the option stating that nuclear gauges cannot be shipped by air is also incorrect, as there are specific conditions under which they can be transported. Lastly, the assertion that they can be shipped internationally without restrictions is misleading; while they can be shipped, they are still subject to international regulations, packaging requirements, and documentation to ensure safety during transit. Therefore, the regulation about cargo aircraft is vital for maintaining safety and compliance in the transport of these sensitive and potentially hazardous items.