Quicksort uses the first element as pivot.
The maximum number of comparisons occurs when each partition is as unbalanced as possible.
Option (A) is:
$22,25,56,67,89$
This array is already sorted.
The first pivot is $22$, which is the smallest element.
Therefore, the partition sizes are: $0$ and $4$
The next pivot is $25$, again the smallest element of the remaining subarray.
The partition sizes become: $0$ and $3$
This continues throughout the algorithm.
The comparisons are therefore: $4+3+2+1=10$
In general, for $n$ elements:
$(n-1)+(n-2)+\cdots+1=\frac{n(n-1)}{2}$
Thus, an already sorted array produces the maximum number of comparisons when the first element is always selected as pivot.
