Which of the following measures best demonstrates the Romans fear of officials gaining too much power? I think it's limits on time in office

Yes, you are correct. Limits on time in office were one of the measures that best demonstrated the Romans' fear of officials gaining too much power. This practice, known as term limits, ensured that no individual could hold a specific office for an extended period, reducing the risk of one person amassing too much authority and becoming a potential threat to the Roman Republic or Empire.