She was in a state of anxiety when I met her.

Answer: Option C

Anxiety : a feeling of worry, nervousness, or unease about something with an uncertain outcome.
Pleasure : a feeling of happy satisfaction and enjoyment.
Happiness : the state of being happy.
Relief : a feeling of reassurance and relaxation following release from anxiety or distress.
Laughter : the action or sound of laughing.

Antonym of Anxiety is Relief