The unification of Mongol tribes by Termujin led directly to the formation of the Mongol empire. Option A is correct.
The Mongol empire was founded by Genghis Khan in 1206. It streched from the Pacific Ocean in the east to the Danube River and the shores of the Persian Gulf in the west. It became the largest contiguous land empire in history. The Mongol Empire arised from the unification of several nomadic tribes in the Mongol homeland.
