What are weep holes designed to do?

Answer: B — Allow water to drain from behind abutment

Weep holes are specifically designed to allow water to drain from behind bridge components, such as abutments and retaining walls, effectively managing water that could accumulate in these areas. When water builds up behind an abutment, it can lead to increased pressure on structural elements, potentially compromising the stability and integrity of the bridge. By providing a means for this water to escape, weep holes help maintain the structural integrity of the bridge and prevent erosion and other water-related damage. The other options do not accurately describe the primary function of weep holes or relate to their engineering purpose. While preventing flooding of the bridge deck and supporting structural load are important considerations in bridge design, those purposes fall outside the specific role of weep holes. Additionally, improving aesthetic appearance is not relevant to weep holes, as their function is focused on structural health rather than visual appeal.