Concept:The word needed is one that describes a visible look on a person's face showing emotion.Explanation:An expression is the look on someone's face that conveys a particular emotion.In this sentence, "from the expression on her face" clearly shows that Binta's happiness was visible.A "picture" is an image, an "appearance" is how someone looks in general, and a "sight" is something seen.None of these fit the context of showing a specific emotion on the face.Answer:C. expression