What does `items.insert(1, "x")` do when `items` is `["a", "b"]`?
It changes the list to `["a", "x", "b"]`.✓Correct answer
It changes the list to `["a", "b", "x"]`.
It replaces `"b"` and leaves two elements.
It raises IndexError because index 1 is occupied.
Explanation
Insertion at index 1 places the new value before the element that was at that index, producing `a`, `x`, `b` in order. It does not replace `b`, because slice or indexed assignment would be needed for replacement.