Which of the following defines in a shorthand form the width, style, and color for the top border of an element?

border-style: solid black;

The border-top-style, border-right-style, border-bottom-style, and border-left-style properties are all longhand properties that specify the style for the top, right, bottom, and left borders of an element, respectively. They take the same values as the border-style property.

For example, the following CSS code will create a solid black border for the top and bottom borders of an element, and a dashed border for the left and right borders:

border-top-style: solid black;
border-bottom-style: solid black;
border-left-style: dashed;
border-right-style: dashed;

The border-up property is not a valid CSS property.