What book is the phrase “The essential is invisible to the eyes” from?

Question: What book is the phrase “The essential is invisible to the eyes” from?

Options:

The fault in our stars
The little prince
The last song
A walk to remember

Correct answer:

The little prince

Other mobile game answers:
Find the answers to emoji quiz answers, 600 celebs, guess the gif answers.
You can find other questions and answers of trivia crack at trivia crack cheats (other languages are also available, for this game).