What DOT label indicates a radiation level of 10 mR/hr at a distance of 1 meter?

The correct choice is indicated as Radioactive II (Yellow). This label is used for packages that have been classified to emit a radiation level between 1 and 10 mR/hr at a distance of 1 meter. Specifically, a level of 10 mR/hr falls at the upper threshold of this category, which makes it appropriate for the Radioactive II classification.

Radioactive I (White) is reserved for materials with very low radiation levels, typically at or below 0.5 mR/hr at 1 meter. This classification is for packages that present minimal hazard. On the other hand, Radioactive III (Yellow) is designated for packages that emit higher levels of radiation, specifically above 50 mR/hr at a distance of 1 meter, which exceeds the conditions of the question. The Radioactive IV (Red) classification does not exist in the standard Department of Transportation (DOT) labeling system for radioactivity.

In summary, the Radioactive II label (Yellow) accurately represents the radiation hazard posed by a package emitting 10 mR/hr at 1 meter, placing it in the appropriate category of risk for transport and handling.