Letter b on the map labels which feature of the middle east

That is the Euphrates River if you want to check for yourself then go to this link it has a map and it also shower the rivers near by

https://www.google.com/search?q=middle+east+map+Syria+river+name&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjnocy2u5XdAhUKbK0KHQ7sC2sQ_AUICigB&biw=1514&bih=891#imgrc=4dggm7IZF65l9M:

It is the first map.

[content deleted] - user123802726recklesschicken

answer; a cost benefit analysis;