Which component helps to prevent debris from entering scuppers?

Answer: A — mesh cover

A mesh cover is designed specifically to prevent debris from entering scuppers, which are openings in a bridge deck that allow water to drain off. By utilizing a mesh cover, larger debris such as leaves, twigs, and trash is effectively filtered out, ensuring that the scuppers can function properly without blockage. This is crucial for maintaining the drainage system, as blocked scuppers can lead to water accumulation on the bridge deck, resulting in potential structural damage and safety hazards. Although other components like sediment traps may assist in managing sediment and contaminants in a drainage system, they do not serve the direct purpose of covering scuppers to prevent debris entry. Similarly, drainage valves and grading systems play their roles in water management, but they do not provide the protective barrier that a mesh cover does against debris.