I believe the answer you are looking for here is the rising air near the equator. (I don't exactly know if this is the correct answer but I do know that prevailing winds can vary due to the uneven heating of the Earth) so you can make your choice based on my knowledge but you should also perhaps wait for another person's opinion.
I hope this helps and that you have a great day! :)
Latitude and the Earth's movement
determines the direction of prevailing winds
Option B
<u>Explanation</u>:
Prevailing winds are the kind of surface winds that are directed in particular direction. These winds occur due to varied patterns of earth movement . Eastern and western winds are present predominantly in low and high latitudes respectively. Various types of breezes also aid in movement of winds. For example sea breeze helps in prevailing winds which are light in nature. To display the direction of prevailing winds various tools are used such as wind Roses. Winds differ in in latitudes due to rotation of earth.
What first comes to my mind is that one or more rivers feature very prominently in these civilizations: the Nile in the Egyptian and the Tigris and Euphrates in the Babylonian.
