A candidate repeatedly shakes a leg during an interview. What may this most likely indicate?

Correct answer: Restlessness or nervousness

The governing concept is interpretation of non-verbal behaviour in context. Repeated leg shaking is often associated with physical restlessness, tension, or nervousness, especially in an interview situation. Therefore option D is the most likely answer. It does not reliably prove happiness, agreement, or complete calmness. Other causes, such as habit or discomfort, are possible, so the observer should consider the whole situation rather than one cue alone.