Find the year Kunal was born.

Statement 1: Kunal is 25 years younger than Manoj.

Statement 2: Raju, who was born in 1975, is 14 years older than Manoj.

Statement 1: It is given that Kunal is 25 years younger than Manoj, but we do not know the year in which Manoj was born. So, the year cannot be determined using Statement 1.

Statement 2: There is no information given in statement 2 about Kunal. So, we cannot determine the year Kunal was born.

Using statement 2, we can calculate the year in which Manoj was born as 1975 + 14 = 1989, and using statement 1, we can calculate the year in which Kunal was born. It can be calculated as 1989 + 25 = 2014.

So, using both statements, we can calculate the year in which Kunal was born.

Hence, the correct answer is option D.