Quezi, an East Asian Country, Borrows $300 Million from Muranico

Quezi, an East Asian country, borrows $300 million from Muranico, a North American country, to fund its infrastructure projects. Quezi exports petroleum worth $700 million to Muranico and other countries. Besides this, Quezi provides foreign aid worth $40 million. In this scenario, this flow of money into and out of Quezi can be measured by _____.

A) articles of organization
B) opportunity cost
C) the balance of payments
D) the balance of trade