Correct Option (B)
Ena's present age is 13 years. Her mother is 24 years older than Ena, making the mother's present age 13 + 24 = 37 years.
The mother is 3 years younger than the father, so the father's present age is 37 + 3 = 40 years.
Ena was born 4 years after her parents' marriage. Since Ena is currently 13 years old, the total duration elapsed since her parents' marriage is 4 years (pre-Ena's birth) + 13 years (Ena's current age) = 17 years.
Therefore, the father's age at the time of marriage was his present age minus the total elapsed time: 40 - 17 = 23 years.
Incorrect Options:
Options (A) 22 years, (C) 24 years, and (D) 25 years are incorrect. These values would arise from miscalculations in determining the present ages of Ena's parents or an incorrect assessment of the total time elapsed since their marriage. The precise application of the given conditions leads exclusively to 23 years as the father's age at marriage.