An Example of an Import of a Service in the U.S

An example of an import of a service in the U.S. balance of payments would be when

A) an U.S. resident purchases a Japanese stereo.
B) a Norwegian traveling in the United States rides a trolley car in San Francisco.
C) a U.S. resident buying insurance from a firm in Toronto.
D) a U.S. firm purchases 100 shares of a Dutch firm.