Institution: SONALI BANK LTD Exam: Sonali Bank Ltd - Assistant Programmer - 26.08.2016 ||
Topic: ICT (তথ্য ও যোগাযোগ প্রযুক্তি), Subject: Computer and ICT (তথ্য ও যোগাযোগ প্রযুক্তি)

Best Answer Explained in Below-:

The statement that the worst-case scenario for the Quicksort algorithm occurs with random data is a bit misleading; actually, the worst-case performance of Quicksort typically arises from specific patterns of input data rather than a completely random dataset.

In Quicksort, the choice of the pivot is crucial. If the pivot is consistently the smallest or largest element (which can occur in sorted or nearly sorted data), the algorithm degrades to O(n^2) complexity, as it effectively processes n partitions one element at a time. This scenario presents the deepest recursion tree possible, translating to inefficient performance.

On the other hand, random data isn't inherently the worst case for Quicksort. In fact, Quicksort is designed to handle average-case scenarios well, with average complexity of O(n log n). Randomized pivot selection, such as picking a pivot at random, generally results in better performance across varied datasets, reducing the chance of hitting the worst-case situation.

Therefore, it’s more accurate to say the worst-case scenario occurs with sorted or nearly sorted data (such as in option A) rather than random data. Thus, the best understanding is that answer D, "None of the above," would be a more fitting choice if we were considering actual worst-case scenarios.