Construction of a seawall produces an effect analogous to what kind of natural coastal feature?
◦ a barrier island, which forms an artificial beach at the front of the seawall
◦ a spit, formed by sand moving by longshore drift accumulating along the opening of a tidal channel
◦ a sea cliff producing erosion at the base of the sea cliff (i.e., the seawall)
◦ an island offshore breaking waves and trapping sand behind to form a tombolo