The birth of his child decidedly proved to be an auspicious event in his life.

  1. precious
  2. ominous
  3. useless
  4. unforgettable


Auspicious means conducive to success; favourable. Ominous means giving the worrying impression that something bad is going to happen. Antonym of auspicious is ominous or inauspicious.

The correct option is B.