What is the most likely meaning of the phrase lower its sights as it is used in this passage?

These are the indicators of crisis, subject to data and statistics. Less measurable, but no less profound, is a sapping of confidence across our land; a nagging fear that America’s decline is inevitable, that the next generation must lower its sights.

1. inherit the mistakes of those who came before
2. perform jobs that no one else wants to do
3. settle for something less than originally strived for or hoped for
4. accept that sometimes progress is not an option