Brush fence while inexpensive to implement, would not be a permanent solution. Hence the correct option is c.
The Brush Fence method, denoted by option C, is an approach to coastal erosion prevention that involves the use of Christmas trees or discarded lumber arranged in a "crib" fashion. These structures are typically 4 feet wide and 72 feet long, positioned perpendicular to the shoreline. The primary purpose of the brush fence is to trap and accumulate sediment that is moving alongshore in the littoral current.
While the brush fence method is relatively inexpensive to implement, it may not represent a permanent solution to coastal erosion. The effectiveness of brush fences is influenced by factors such as weather conditions, wave action, and the gradual degradation of the organic materials used. Over time, the Christmas trees or lumber may break down or shift position, reducing their ability to serve as a lasting barrier against erosion. Hence the correct option is c.