Which ASTM standard applies to samples for structural steel plates according to the relevant specifications?

The correct answer is based on the standards established by ASTM for structural steel plates, which set the requirements for materials used in construction.

A36, A283, and A242 are all ASTM standards that specifically address different grades of structural steel. ASTM A36 is a widely used structural steel specification that covers carbon structural steel shapes, plates, and bars of structural quality for use in riveted, bolted, or welded construction. ASTM A283 specifies the requirements for low and intermediate strength carbon steel plates, which are suitable for use in certain construction applications. ASTM A242 is for weathering steel used in structural applications exposed to the elements, which is designed to develop a protective rust layer that improves durability.

These standards provide the necessary mechanical properties, composition requirements, and testing methods needed to ensure the materials meet safety and performance criteria for structural integrity. Therefore, they are applicable to samples of structural steel plates as indicated in the question.

The other options list ASTM standards that, while relevant to various steel products and applications, do not specifically focus on structural steel plates in the same way as the mentioned standards do. This is key in understanding why A36, A283, and A242 is the most appropriate selection for the question regarding structural steel plate samples.