The correct answer is C. padding.
Padding is the space between the content of an element and its border. It is used to add space around the content of an element, and can be used to create a border around the content.
Border is the line that surrounds an element. It can be used to add a border around an element, and can be used to create a frame around the element.
Margin is the space between an element and its surrounding elements. It is used to add space around an element, and can be used to create a gap between elements.
Resize is not a CSS property.