What applies to this road that is outside of a built-up area?

On roads outside built-up areas where there is a continuous solid line separating the lanes, the only reason you are allowed to cross that line is to turn left. Overtaking or driving over the line due to a traffic jam is not permitted. This rule helps maintain traffic safety on faster rural roads. So if you selected answer 1 (to perform a left turn), you are correct. Remember for similar questions: crossing a solid line outside built-up areas is only allowed for left turns.