What is the shape of a warning sign?

What is the shape of a warning sign?

1. A square sign with a vertical diagonal, double border, a thick black inner border, a thin white outer border, a yellow background, and a black symbol or sign.
2. A circular sign with a white border, blue background, and white symbol.
3. A rectangular/four-sided sign with a white border and red background.

Correct answer

A square sign with a vertical diagonal, double border, a thick black inner border, a thin white outer border, a yellow background, and a black symbol or sign.

This is the correct answer for the Cambodian driving theory test. Questions are drawn from the official Ministry of Public Works and Transport sign library and road rules.