For each of the following changes (other things equal), has the value of the country's current account balance increased (become more positive or less negative), decreased (become less positive or more negative), or stayed the same?

a. Net foreign investment out of the country increases.

b. Exports of goods and services increase by $10 billion, and imports of goods and services increase by $10 billion.

c. National expenditures on goods and services ( E ) increase by $150 billion, and production of goods and services ( Y ) increases by $100 billion .

d. To assist recovery from a foreign disaster, the country gives a foreign transport authority a collection of transport equipment that has been produced in this (donor) country and that is valued at $500 million.