People Living in the Town of Norwich, England, Have Begun

People living in the town of Norwich, England, have begun a system of trade called the LETS, which allows people to enter into exchanges without using the British pound. Members offer a particular service, such as babysitting, gardening, and plumbing for which they get Croy credits. They can then use these Croys to buy services from other people. Does this system represent what economists call barter?

A) No, to be true barter, the exchange rate between the Croy and the British pound must be flexible.
B) No, this group has merely replaced one money, the pound, with a less flexible medium of exchange that they call the Croy.
C) Yes, because it does not use the true money, the British pound.
D) Yes, because the Croy is not real money but just a bookkeeping account.