Statement i is TRUE: Merge Sort is stable because it preserves the relative order of equal elements during the merging process (provided the logic handles the left sub-array first).
Statement ii is FALSE: The standard implementation of Merge Sort requires an auxiliary array of size $n$ to perform the merge step, leading to a space complexity of $O(n)$, not $O(1)$.
Statement iii is TRUE: Merge Sort consistently divides the array in half ( $\log n$ levels) and performs $O(n)$ work at each level to merge. This holds true for the best, average, and worst cases, resulting in $O(n \log n)$.
Statement iv is FALSE: An "in-place" algorithm is one that requires a constant amount of extra space. Since Merge Sort requires $O(n)$ extra space, it is not considered an in-place algorithm
