The cause-and-effect diagram that best illustrates one main effect of informed citizens on the political system is:
D. Citizens make informed voting decisions.
Explanation:
1. Informed citizens who understand political issues critically are more likely to make informed decisions when it comes to voting.
2. When citizens can think about political issues critically, they are able to assess candidates' platforms, policies, and track records more effectively.
3. This leads to a more educated electorate that can make choices based on a deeper understanding of the implications of their votes.
4. Ultimately, when citizens make informed voting decisions, they contribute to a more effective and responsive political system that reflects the will of the people.