If Radix sort is used to sort an array of n integers which are in the range 
,
where d is some function of input size, the time taken would be?
(A) 
(B)
(C) 
(D) 
I know that Radix sort takes $\theta(d(n+k))$ times over 'd' digits of numbers, and the counting sort it uses takes $\theta(n+k)$ times in each pass where k represents the range of input numbers.
I am unable to solve this.
Please help.
