Question

The best reason why direct democracy would not work well in the United States is that

it would be impossible to get each and every citizen to vote.
the national government can not listen to the ideas of individuals.
it may have worked in ancient Greece, but it can not work in the modern world.
large groups of voters would be difficult to manage.

Answer 1

The best reason why direct democracy would not work well in the United States is that "large groups of voters would be difficult to manage", since the population of Ancient Greece, where it was practiced, was much smaller than the current US population.