This sounds like a silly question, but our teacher said it should be 2) in the image below:
She said 1) is wrong! I almost fell off my chair. I've never seen it printed with the strokes. Not in novels, nor papers or magazines, nor textbooks, never. She tried to convince me (unsuccessfully) that this was because computer and typewriter fonts have dots for an umlaut instead of the strokes. IMO that's no explanation at all: if they really want strokes there is nothing that stops them from designing such a font, right? So now I'm confused, which should it be: dots or strokes?