Hard wired control involves only hardware, whereas microprogramming is software approach. So, hardwire control should be faster than both microprogramming approaches.
Between vertical and horizontal microprogramming. Horizontal is faster because in this control signals are not encoded whereas in vertical microprogramming to save memory signals are encoded. So, it takes less time in horizontal microprogramming because decoding of signals is not required. Therefore, final order is :
hard wired control > horizontal microprogramming > vertical microprogramming
Correct Answer: $B$