Answer : Option B

Explanation :

The following program will make you understand about ## (macro concatenation) operator clearly.

 #include
 #define FUN(i, j) i##j 

 int main() 
 {    
      int First   = 10;   
      int Second  = 20;   
    
     char FirstSecond[] = "FresherGATE";  
    
     printf("%s\n", FUN(First, Second) );    

      return 0;
 }
 
  Output: 
  -------
  FresherGATE

The preprocessor will replace FUN(First, Second) as FirstSecond.

Therefore, the printf("%s\n", FUN(First, Second) ); statement will become as printf("%s\n", FirstSecond );

Hence it prints IndiaBIX as output.

Like the same, the line printf("%d\n", FUN(va1, 2)); given in the above question will become as printf("%d\n", va12 );.

Therefore, it prints 20 as output.