Two days ago, Citibank furnished Walmart with a letter of credit and documentations for a banker's acceptance so that Walmart could import USD 25 million worth of Brie from a cheesemaker in France. In this instance, Citibank was performing the function of ____________________.

Group of answer choices:

a)minimizing foreign exchange risk

b)international investment banking

c)transferring purchasing power

d)financing international inventory in transit