Final answer:
The true statement is that B) you must stop at a railroad crossing when directed to do so by a flagger or stop sign.
Step-by-step explanation:
The statement that is true is option B) You must stop at a railroad crossing when directed to do so by a flagger or stop sign.
When approaching a railroad crossing, it is important to follow the instructions given by a flagger or a stop sign. This is to ensure the safety of both drivers and train passengers. Ignoring these instructions can lead to accidents and may result in serious consequences.
For example, if a flagger signals you to stop, it is essential to obey and wait until the flagger instructs you to proceed. This is because a train may be approaching, and crossing the tracks when a train is nearby can be extremely dangerous.