Could you please explain your calculations?

You are given the data concerning the international economic transactions of Country X during a year Suppose that there are no errors and omissions Exports of goods: $20 000 Balance on goods and services (deficit): $15 500 Exports of services: $8000 Imports of services: $3500 Investment income received from abroad: $4500 Primary income balance (surplus): $2500 Secondary income balance (deficit): $2000 Increase in foreign owned long-term domestic assets: $7500 Increase in domestically owned short term private assets abroad: $12 500 Increase in domestically owned long term official assets abroad: $4500 Foreign Central Banks acquisition of domestic assets: $7500 Domestic Central Bank's acquisition of international assets: $2500 What is the value of official settlements balance (change in reserves)? Select one: a. $ 5 000 O b. $ 7 000 O C. $ 3 500 O d. $ 2000