Which of the following would not count as a barter transaction?
- Aa car repairer undertaking the annual service on a plumber’s van in return for the plumber fitting a new sink in the car repairer’s kitchen
- Ba consumer negotiating with a shopkeeper and buying a pair of trousers at US$10 rather than the asking price of US$30
- Ca graduate student exchanging a set of textbooks for a radio with a student about to start the course
- Da train company allowing a phone company to advertise on its trains in return for the right to advertise on the phone company’s website