In what situations may I allow a cyclist to be pulled along?

You answered correctly. Allowing a cyclist to be pulled along by a motor vehicle is never permitted in Germany, regardless of speed or road type. This rule exists because being pulled creates a high risk of falls and accidents, endangering both the cyclist and others. Safety always comes first, so such actions are strictly prohibited under German traffic regulations. If you see a question about pulling cyclists, always remember: it is not allowed under any circumstances.