Floods. Monsoons are massive rainstorms which can often bring devastating floods to low ground. Hope I helped!
The best reference to use will be AN ATLAS.
An atlas is a collection of maps. A map is a pictorial representation of an area of land or sea which shows all the physical features of that particular place. Many information about different places can be obtained from maps and these include the longitudes of different places.
I think its B but possibly C
