Answer:
In Athens, all citizens have a responsibility to take part in government.
Step-by-step explanation:
This statement best sums up the main idea of the passage because the passage suggests that in Athens, all citizens have a responsibility to take part in public life and government. The passage states that citizens do not "allow absorption in their own various affairs to interfere with their knowledge of the city's life" and that those who hold aloof from public life are considered "useless." These statements imply that all citizens in Athens are expected to be actively involved in the life of the city and to contribute to the government and public life of the community.