What factors enabled rulers of land based empires in the early modern era to establish or maintain their authority?

The use of "gunpowder" aided the rulers of the land in their territorial expansion. It was coupled with new military technology and strategy which allowed them to establish authority. Such authority was also maintained with the existence of slaves who were forced to work (such as the Ottoman Empire). This is also evident with the presence of "serfs" through the "feudal system" in the Russian Empire.

Explanation:

The land-based empires in the "Early Modern Era" were the empires of Russia, China and the Ottoman.

In Russia, the "czars" remained to be the ruling class. They were autocrats who had dictatorial power. Two of the popular czars in those time were "Peter the Great" and "Catherine the Great."

In China, the Ming Dynasty took over the land controlled by the Mongols. They continued the territorial expansion.

The "Ottoman Empire" also expanded its territories through a number of different wars, until the end of the World War II. Their basis for social structure were religion and education. Muslims have lesser tax rates and educated families have higher statuses.

the percentage of students at the school need special diets is

c) 10 percent

the answer is a, salt plain