Which of the following statement(s) is/are true?
(a) Quicksort and merge sort are both examples of divide and conquer algorithms.
(b) If we randomly choose a pivot element each time, quicksort will always terminate in time $O(n log n).$
(c) For every fixed strategy to choose a pivot for quicksort, we can construct a worst case input that requires time $O(n)$.
(d) If we could find the median in time $O(1)$, quicksort would have worst case complexity $O(n log n)$.
plese give answer and explain it why ?