Answer : Option B is correct. 
Explanation :
Since we have given that 
f(x) = x+1
and 
g(x) =x
and when we divide f(x) with g(x) i.e.
 

And we know the division algorithm , i.e.
 ,
, 
Where q(x) represents quotient and r(s) denotes remainder 
So, we write it in this manner ,

Hence, Remainder = 1
So, Option B is correct.