The correct answer is C. font-style.
The font-style property is used to specify the style of a font. It can be used to make a font italic or oblique. The value for the font-style property can be italic or oblique.
The font-family property is used to specify the family of fonts that should be used to render text. The value for the font-family property can be a comma-separated list of font family names.
The font-weight property is used to specify the weight of a font. The value for the font-weight property can be normal, bold, bolder, or lighter.
The font-variant property is used to specify the variant of a font. The value for the font-variant property can be normal, small-caps, or inherit.