Much to the chagrin of his parents, Ajit married a very poor girl.

Answer: Option C

Chagrin : annoyance or distress at having failed or been humiliated.
Satisfaction : fulfilment of one's wishes, expectations, or needs, or the pleasure derived from this.
Relief : a feeling of reassurance and relaxation following release from anxiety or distress.
Pleasure : a feeling of happy satisfaction and enjoyment.
Excitement : a feeling of great enthusiasm and eagerness.

Antonym of Chagrin is Pleasure