Which option correctly states a prerequisite for performing binary search on a collection?

• A. The data must be unsorted.
• B. The data must be randomly shuffled.
• C. The data must be stored in a linked list.
• D. The data must be sorted.

Answer: (D)

Binary search relies on the data being in a consistent order so you can rule out half of the remaining elements after each comparison. When the collection is sorted, comparing the target to the middle element tells you whether the target would lie to the left or to the right, allowing you to discard half the data and continue the search efficiently. If the data aren’t sorted, that middle comparison no longer provides reliable guidance about where the target could be, so you’d end up checking elements one by one. Also, the method assumes you can quickly access the middle element, which is straightforward with arrays (random access) but not as efficient with a linked list, further reinforcing why a sorted, random-access structure is the practical prerequisite.