The answer to this question is A. Jet streams
Jet streams are located near the altitude of the upper troposphere. It's a movement of wind that travels from one side of the planet hemisphere to another. The movement of jet streams will bring up different temperature of air which could influence the weather that exist in certain regions.
The troops tried to send supplies but there was a blockade and they were not able to deliver them.
hope it helped <span />
<span>The
challenge that early farmers did not face as a result of the change from a
nomadic lifestyle to an agricultural lifestyle could be early death caused by
disease. Because in agricultural lifestyle, the nomads are now trying to
establish a boundary between their food to eat and food to sell or exchange. It
could also be a challenge for them to clear and cultivate lands because of the
lack of resources.</span>
