I want to get this for the benefit of having unlimited public transport and discounts at museums starting October 5. Since I plan to go to Potsdam one of those days, the difference in price between AB & ABC is €3 so I might as well get the ABC 5 day pass. May I assume that all public transport in Potsdam is included?
Next, should I buy this pass online at Berlin.de or in person? If online, is there an app I need to download or if I buy it on that website, how will I see & have access to this 5 day pass? Or should I buy a ticket in person and if so, where?