Dams have a limited effect on rivers and streams. true or false

I'm pretty sure it is false. Usually dams limit the flow of water from rivers and streams which of course does have a huge effect as this causes cities to be built at lower altitudes and enjoy a lower water level. This effect on the river could be considered limited but in the end the effect is literally just siphoning water from the aforementioned lake into a smaller river. 

So false... depending on how you look at it. 

Ithink the answer is either a , c or d