A floodplain forms where a stream cuts mainly side to side. The correct option among all the options that are given in the question is the second option. These floodplains are very fertile and so great for cultivation of crops. Most of the ancient civilizations started beside floodplains as people could cultivate very easily and fulfill their needs.
Channel Tunnel, CN Tower, Empire State Building, Golden Gate Bridge, Itaipu Dam, North Sea Protection Works (Netherlands), Panama Canal. Hope this helps!
