Another example of a Handling Label could be?

The correct choice, "Keep frozen," is indeed a proper example of a Handling Label. This type of label provides specific instructions on how to store and transport materials that require particular environmental conditions to maintain their integrity or safety. For substances that are susceptible to degradation due to temperature, a "Keep frozen" label is crucial as it alerts handlers to the necessity of maintaining a sub-zero temperature.

In the context of dangerous goods or materials, handling labels serve to minimize risk and ensure that the materials remain stable and safe during transportation. A label indicating that a product should be kept frozen informs handlers to store it in a freezer or cold environment to prevent spoilage or other adverse reactions.

Other options present relevant safety guidance but do not specifically align with the defined context of a handling label. "Handle with caution" suggests a general precaution but lacks the specificity of temperature control. "Do not open until used" provides information about the product's use but is not a direct instruction related to storage or handling conditions. Similarly, "Keep away from sunlight" advises against exposure to light, yet it does not imply the same level of necessity as the freezing requirement. Thus, while they may be important in various contexts, they do not exemplify a Handling Label as effectively as "