【单选题】In Europe and Asia, the first 'medium of exchange' or 'standard of value' was not gold or silver, but cattle. In other parts of the world, however, such different commodities as salt, shells, stones a...
A.
people used to prefer gold and silver as their medium of exchange
B.
money was invented first in Europe and then in Asia
C.
coins appeared as the result of inconvenience in exchange
D.
the earliest coins were made quite differently from those we are using now