Sorting

Let $P$ be a quicksort program to sort numbers in ascending order using the first element as the pivot. Let $t_1$ and $t_2$ be the number of comparisons made by $P$ for the inputs [1 2 3 4 5] and [4 1 5 3 2] respectively. Which one of the following holds?

You have an array of $n$ elements. Suppose you implement quicksort by always choosing the central element of the array as the pivot. Then the tightest upper bound for the worst case performance is