When may you use the right-hand hard shoulder?

Your answer is correct. According to German traffic rules, the right-hand hard shoulder may be used for stopping and parking (option 1), typically in emergencies or when explicitly allowed. It can also be used by slow-moving vehicles (option 2) to avoid obstructing faster traffic, but only where permitted and safe to do so.

However, the right-hand hard shoulder is not allowed to be used for overtaking (option 3). Overtaking must typically be done in the designated driving lanes.

Understanding this helps you distinguish the special functions of the hard shoulder: it is primarily a safety and emergency lane, not a normal lane for overtaking. Always watch for signs indicating permitted use.