I dont know this one but someone will anser this
It was primarily "<span>d. the vulnerability to invaders from the north", since the Mongol territory was rapidly expanding--making the Mongol warriors all the more powerful. </span>
This is referred to as Nationalism. It is the notion or belief that one's country possesses qualities or traits not found in that of other nations. It often promotes a sense of exceptionalism and superiority; therefore, it has often led to <em>Chauvinism </em>which is a rather hostile form of Nationalism and is often utilised as a political tool to achieve an ends.