What is formed when white is added to brown?

Correct answer: Light brown

The governing concept is colour value and tint. White increases the lightness of an existing colour, so adding it to brown produces a lighter brown. In colour terminology, a tint is made when white is mixed into a hue. Thus option C is correct. Dark brown would require a darker pigment or usually some black, while orange and blue are different hues rather than the expected lightened form of brown.