What Is the Major Difference Between a Direct Democracy and a Representative

What is the major difference between a direct democracy and a representative democracy?

A) In a direct democracy, citizens themselves make decisions, whereas in a representative democracy, citizens choose intermediaries who make decisions for them.
B) A direct democracy is possible only if citizens participate, whereas in a representative democracy, citizen participation is unnecessary.
C) The only major difference between the two is that direct democracies have been around longer than representative democracies.
D) Representative democracy was not practicable in ancient Greece, but direct democracy was.
E) There is no difference between the two types of democracy.