The correct answer is A) decreases the present and future risk to human properties.
It is best to say that the protection to properties offered by sea walls along coasts decreases the present and future risk to human properties.
If you live by the sea, you probably are familiar with sea walls. This is a vertical structure built to prevent upland erosion and flooding when there is a heavy storm or hurricane season. You can find many of these sea walls along the shoreline in urban places next to the beach. But there are also some negatives of these structures such as an ugly visual impact, placement loss, passive erosion, lost of sand, and loss of ecosystems.
