What is the symbol for a railway crossing?

The symbol for a railway crossing is represented by a crossbuck. This sign is specifically designed to alert drivers and pedestrians to the presence of a railroad crossing ahead, indicating that it is necessary to approach with caution. The crossbuck has a distinctive white background with diagonal black stripes, and it often has the words "Railroad Crossbuck" prominently displayed.

Recognizing this symbol is crucial for safety, as it indicates that a train may be approaching, and drivers must stop and look both ways before proceeding. This helps to prevent accidents at crossings where trains and vehicles may interact. The other options represent different traffic signs that serve other purposes and do not convey the specific warning associated with railway crossings.