SunCo, a U

SunCo, a U.S. corporation, owns a number of patents related to designing sunglasses. SunCo licenses these patents to unrelated parties. SpainCo, a Spanish corporation, paid SunCo $78,000 in royalties related to these licenses. SpainCo uses the patent information in its manufacturing process in its Texas plant. WiscCo, a domestic corporation, paid SunCo $32,000 in royalties related to the licenses. WiscCo uses the patent information in its manufacturing process in its Germany manufacturing plant. How much U.S.-source royalty income did SunCo earn from these licenses?

A) $0
B) $32,000
C) $78,000
D) $110,000