Why was the building of the ataturk dam controversial?
a.
it further complicated relations between israel and the arab world.
b.
people were concerned that it would encourage the depletion of natural aquifers.
c.
desalination is a costly project that requires large amounts of resources.
d.
the river flows through syria and iraq; both depend on the river.

The reason Ataturk Dam was controversial what that, despite the promises of the Turkish government to the contrary, it could lead to water shortages in Iraq and Syria.  During the time that the water reserve behind the dam is being filled, additional water would be absorbed in Turkey, and this would result in  diminished amount of water for Syria and Iraq - the correct asnwer is thus the last answer.