When I looked into her sea green eyes, I was suddenly sure

everything was going to be O. K.

Which Romantic idea is most clearly shown here?

The correct answer is: intuition

Explanation:

Intuition was one of the most important characteristics of Romanticism.

The Romanticist writers considered intuition very important, even more important than rational perceiving of things. They considered that the intuition leads one to the truth.

This sentence clearly shows that the author is using his intuition to assume that everything will be o. k. and that his situation will have a positive outcome.