What is default css display value for react web application?

I was passing upwork test for react.js and I have got this question, I realy don't know, and google/react documentation don't help me. Can anyone know? it is very interesting to me) enter image description here

What is the default value of display in CSS?

The default display value for most elements is block or inline .

Which CSS is used in React?

CSS in React is used to style the React App or Component. The style attribute is the most used attribute for styling in React applications, which adds dynamically-computed styles at render time.

What is the default CSS?

The :default CSS pseudo-class selects form elements that are the default in a group of related elements.

A React application is not an element. It doesn't have a default value for any CSS property.