You present the Rent$-$a$-$Scooter idea including scooter, backend, and various mobile apps to the mayor of your hometown. She agrees to let you use her city for a test phase, but on one condition: Es muss sicher sein. $($It has to be secure and safe$)$ usses an$.$ ware$-$Life$-$Cycle a$)$ Refine the given abstract requirement into at least seven more specific requirements. Classify the resulting requirements as either functional or one of the non$-$functional requirements in van Lamsweerde$$s taxonomy. b$)$ Formulate guidelines under which circumstances a distinction between functional and non$-$functional requirements is useful. What are benefits of such a distinction?