Investigating the evolution of the Russian Empire's methods of political control suggests which of the following about political control in general?
a) Reimagining the ruler's role and title ensures that no one will take power from that ruler
b) Requiring people in a territory to give tribute or pay taxes is not beneficial to a country
c) Very little change happens over the course of a ruler's time in power.
d) Rulers of a country are not only the people with political power in a given state.