Which detail best supports this central idea?

Thomas More's Utopia was written as a social critique.

"Utopia" is a Greek word that means "no place."

An emphasis on nutrition would be important in this society.

Everyone has a different idea about a perfect society.

I had to look to see if I could find what the central idea was that this question is asking about. If it is - In my own personal utopia, health and nature would be top priorities, then the answer would be the third option an emphasis on nutrition would be important in this society. Thomas More is talking about how health and nature would be very important in his own idea of a personal utopia, therefore he is talking about nutrition.