What is the typical average-case time complexity of quicksort and what pivot strategy helps achieve it?

What is the typical average-case time complexity of quicksort and what pivot strategy helps achieve it?

• A. Average-case time complexity is O(n log n); use a good pivot such as median-of-three or random pivot.
• B. Average-case time complexity is O(n^2); pivot choice does not matter.
• C. Worst-case time complexity is O(n log n) with a bad pivot.
• D. Time complexity is O(log n) for all cases.

Answer: (A)