One Splay Can Hurt

You splay a node in an $n$ -node splay tree that is currently one long left-leaning path. What does that single operation cost, and what is the tree afterwards?

$O(\log n)$ rotations. The $O(\log n)$ is worst case, no potential is needed to pay for it, and the tree comes out roughly balanced.

$\Theta(n)$ rotations. The $O(\log n)$ is amortized, the potential stored in the path pays for it, and the tree comes out roughly balanced.

$\Theta(n)$ rotations. The $O(\log n)$ is amortized, the potential stored in the path pays for it, and the tree comes out still one long path.

$\Theta(n)$ rotations. The $O(\log n)$ is worst case, no potential is banked along the path, and the tree comes out roughly balanced.