The Structured Minimum

**Scenario.** A divide-and-conquer solution fails only when n ≥ 16, never below. What is the right minimal-case hunt? **Which approach is the best fit? The program only needs to print the letter.** **A)** Keep testing random n = 15 inputs **B)** Build the structured case: the smallest complete recursion depth (n = 16 = 2^4) with a pattern that forces the failing merge — e.g., all elements arranged to maximize cross-half interaction **C)** Give up and submit **D)** Test n = 1000 to confirm scale sensitivity