There are of course exceptions to this rule - a pentagonal County Route marker isn't (typically) a greater threat than a standard square route marker, and even though they have only 3 sides, the YIELD and No Passing Zone signs are still rather important (and the pennant shape of the NPZ sign serves as a sort of "get ...
In 1970 when the Aswan High Dam was completed, the annual Nile floods and sediment stopped for most of Egypt's civilisation which lived downstream. In addition to creating electricity, the dam allowed Egyptians to control the flow of water and build upon the Nile's banks with certainty that it wouldn't be flooded.
I'm sorry I thought I knew the answer sir.
Answer:
Out of the available options, I would say option A.