Solution : 

Let us take Chandan's age as 'x' , Ankit's age as 'y' , Sumit's age as 'z' and Khushboo's age as 'k' .

It is given that, 

Chandan is 2 years older than Ankit 1 ===> $x = y + 2$

Chandan is 1 year younger than Sumit 2 ===> $x = z - 1$

Ankit is twice as old as Khushboo 3 ===> $y = 2 k$

Khushboo's age is $25$ years, so $y = 2 × 25 = 50$

Substituting the value of 'y' in eqn 1 we get,

$x = 50 + 2 = 52$

$x = 52$

Substituting the value of 'x' in equation 2 we get, 

$52 = z -1$

$z = 52 + 1$

$z = 53$

So, Sumit's age is $53 $

The correct option is 2).53