Many historians now believe that intercontinental trade along the coast of East Africa began in the first century CE, much earlier than was once thought. What archaeological evidence led historians to this conclusion? A) ruins of storehouses and trading equipment that can be carbon-dated to before the European Middle Ages
B) detailed records of trade transactions, some of them dating back to the first century
C) pottery that historians believe was used to store gold and other currency for use in trade
D) artifacts from the first century that reveal a civilization too advanced and wealthy to be built on local trade alone