In the balance of payments, if there are no statistical errors or discrepancies, which of the following is TRUE of the sum of the capital account balance, the current account balance, and the official reserve transactions account balance?
a. This sum must always be zero, because the sum of all surplus and deficit items associated with cross-border transactions must equal zero.
b. This sum is either positive or negative, depending on whether the sum of all surplus and deficit items associated with cross-border transactions is positive or negative.
c. This sum is positive only if the U.S. government operates with a budget surplus.
d. This sum is positive only if the U.S. government operates with a budget deficit.