border-color
border-img
border-visual
border-style
Answer is Wrong!
Answer is Right!
The correct answer is: D. border-style
The border-style property defines the visual style of up to four different sides of a border. It can be used to set the border to solid, dashed, dotted, double, groove, ridge, inset, or outset.
The border-color property defines the color of the border. It can be used to set the border to any color, including transparent.
The border-img property defines the image that is used for the border. It can be used to set the border to any image, including a transparent image.
The border-visual property is not a valid CSS property.