A package shows a red diamond with a flame. How should a basic-module driver treat that label?

1. As a Class 3 flammable-liquid label if the number 3 is shown, or as a flammable-gas (2.1) label if 2 is shown — always read the class number, not only the flame
2. As a Class 8 corrosive label, because red always means acid
3. As a Class 7 radioactive trefoil
4. As a limited-quantity mark that cancels all other duties