If a U.S. company buys an electrical generator made in Japan by a Japanese firm, and the Japanese firm uses the payment to buy stocks issued by a U.S. company then a. U.S. exports and U.S imports increase. b. U.S. exports but not U.S. imports increase. c. U.S. imports but not U.S. exports increase. d. neither U.S. exports nor U.S. imports increase.