The answer to this question is B
The respective area ditches east
I think that the best answer to this is foreign investment: it was the one aspect which has helped Bulgarian economy the most.
The foreign investment is mostly connected to tourism - especially for example when rich western Europeans buy property in Bulgaria for private use.
The closest source of marble for Rome was in the Apuan Alps 350 km north of Rome. In fact it was the Romans who started exploiting marble there.
