What term should replace the question marks on this graph? a) slip stream b) rain shadow c) gulf stream d) curtailing wind which one i need asap

B) rain shadow  should replace the ??? on the chart :)

there is an explationation of this on a site called crash   course world history 1

mali had been a state inside of the ghanaian empire. after ghana fell because of invading forces and internal disputes, mali rose to greatness under the leadership of a legendary king named sundiata, the "lion king." the songhai empire, already weakened by internal political struggles, went into decline.