Final answer:
A yellow pennant-shaped sign indicates a no passing zone, while a round yellow sign signifies a railroad crossing. Proper signage is essential to road and pedestrian safety, such as the use of traffic signals near campuses to help pedestrians cross safely.
Step-by-step explanation:
A yellow pennant-shaped sign means no passing zone. A round yellow sign means railroad crossing. Therefore, the correct answer is c) Railroad crossing, no passing zone. Road signs play a critical role in ensuring the safety of drivers and pedestrians alike. For instance, pedestrian safety is a significant concern near campuses, where students and others must navigate traffic. The installation of a traffic signal at such intersections could reduce the need for pedestrians to dodge traffic, providing them with a safe and appropriate time to cross the street.