The correct answer is C. border-left.
The border-left property defines the style, width, and color of the left border of an element. It can be used to set all three properties at once, or to set only one or two of them.
The syntax for the border-left property is:
border-left: <style> <width> <color>;
The style property can be used to set the style of the border, such as solid, dashed, or dotted. The width property can be used to set the width of the border, in pixels or percentages. The color property can be used to set the color of the border.
For example, the following code will set the left border of an element to be 1px solid black:
border-left: 1px solid black;
The following code will set the left border of an element to be dashed and 3px wide:
border-left: dashed 3px;
The following code will set the left border of an element to be dotted and 5px wide, with a color of red:
border-left: dotted 5px red;