What is "the theory of government in ehich one which one person or party controls all aspects of life"?

The theory of government in which one which one person or party controls all aspects of life is Totalitarianism

This is what you call a dictatorship , with each a group of people(Party) or one person controls the whole government .In this government that person or group has 100% power and no one can take him out of office unless their was a revolution or the dictator(s) change the government, ( which rarely ever happened. If you want a really good explanation of dictatorship I recommended looking up a man called Adolf Hitler he was a dictator during WWll.

This answer would be c

Your answer will be a.