How far in advance should warning signs typically be placed before entering a work zone?

Answer: B — 250 to 500 feet

The correct range for placing warning signs before entering a work zone is typically 250 to 500 feet. This distance is established to give drivers adequate time to react to the upcoming changes in traffic conditions and to prepare for any necessary actions, such as slowing down or merging. This distance allows for sufficient warning based on the expected speed limits and typical driving behaviors. It ensures that motorists have enough advanced notice to adjust their speed and navigate safely through the work zone, which is crucial for reducing the risk of accidents and ensuring the safety of both drivers and workers in the area. Other options, while they may seem reasonable, do not align as closely with the established guidelines for work zone traffic control. Distances that are either too short or too long could lead to confusion or inadequate reaction time, thereby compromising safety.