The correct answer is A) red and white label. Containers of flammable solids must be conspicuously labeled by the shipper with a red and white "Flammable Solid" label, as required by the U.S. Department of Transportation's Hazardous Materials Regulations. This labeling requirement helps to clearly identify the hazardous nature of the contents to ensure proper handling and storage during transportation. The other options are incorrect because: B) green is not the correct color for flammable solid labels, C) orange is used for oxidizing materials, and D) yellow is used for radioactive materials, but not for flammable solids.