What do railroad crossing signals indicate?

Answer: B — Trains are approaching and to stop

Railroad crossing signals indicate that trains are approaching and that vehicles must stop. When these signals activate, typically accompanied by flashing lights and sometimes gates that lower, they serve as a warning to drivers that a train is imminent and it is dangerous to proceed. The purpose of these signals is to prevent accidents by ensuring that vehicles do not enter the crossing when a train is nearby. Understanding this is crucial for any driver, particularly those operating commercial vehicles, as ignoring these signals can result in severe consequences.