Explanation:

- Let F be the father's age and G be the grandfather's age when Rony was born. The ratio is 7:15.

- Hence, F/G = 7/15, so F = (7/15)G.

- When Rony is born, the mother's age (M) is given as 22 years.

- Four years later, Rony is 4, and the grandfather's age (G+4) and Rony's age ratio is 1:16.

- So, 4/(G+4) = 1/16, giving G = 60.

- Substituting G = 60 into F = (7/15)G, the father's age F is 28.

- Therefore, the mother's age is 22, and father's age is 28, giving us a ratio of 28:22.

- Simplifying 28:22 gives 14:11.

So, the correct ratio of ages of Rony's father and mother when Rony was born is 14:11.

Option 2, 14:11, is the correct answer. "."