The correct answer is - F (False).
Floodings are mostly caused by natural events and not by human activity. Most of the floodings appear due to have rainfalls when the rivers get much more water that the capacity of their respective riverbed, nice example of this is when the rivers in India are flooding because of the heavy rainfalls brought by the monsoons. Also, another important factor are the melting snows in the mountains in spring, the snow turns into huge amount of water that makes the rivers flood. There's also some interesting and beezar reasons for flooding like the dams of the beavers which partially stop the river flow and contribute to big accumulation of water that is flooding the space before the beaver dam.