The correct answer is Option b) Genghis Khan united the tribes of Mongolia.
Explanation:
Other options are wrong. For example, it was not Genghis Khan who captured Baghdad but his descendant, Hulagu Khan. He was also not the founder of Yuan Dynasty.
However, his greatest early achievement was the unification of the many nomadic and warring tribes of Mongolia.
Genghis Khan with his charisma and leadership skills was able to unite nomadic tribes in a sparsely populated area and build a strong army out of them.
A united Mongolia was able to face far great foes including the kings of China as well as India and Persia.
The Spanish-American War affected US power in Asia by making the US an important power in Asia. With the acquisition OF Guam and the Philippines the US increased it's influence in Asia .
Negative environmental impacts from unsustainable farming practices include: Land conversion & habitat loss. Wasteful water consumption. Soil erosion and degradation.