Which gauges fall into the Excepted Package category?

The classification of nuclear gauges into the Excepted Package category is determined by their specific design and the activities of the radioactive materials they contain. Gauges that fall under this category are typically small, portable, and designed to contain limited quantities of radioactive materials, which pose a minimal risk during transport.

In this case, the chosen answer includes models like 3660, 4301, 4302, and 4590, which are recognized for their incorporation of low-activity radioactive sources that meet the stringent criteria set for Excepted Packages. This means that these gauges can be transported under less strict regulations compared to other radioactive materials, as their potential risks are significantly lower.

The models listed in the other options do not fit the criteria for Excepted Packages in terms of either their design, the type, or quantity of radioactive material contained within them, which is why they are not included in the correct answer. Recognizing the specifications of these gauges is essential for adhering to safety guidelines and regulatory compliance during transport.