Correct Answer - Option 1 : 5 years
My mother was 23 years old when I was born.
After 6 years my sister was born, at that time my father was 34 years old.
Age of my mother after 6 years = (23 + 6) years
= 29 years
The difference between my parents' age = (34 – 29) years
= 5 years
Hence, ‘5 years’ is the correct answer.