Task: Question Understanding
Input (English): Context : William C. Arthur (4 July 1830 -- 15 November 1886) was a Royal Navy officer who was the namesake of the English name for Lüshunkou, Port Arthur, which changed hands between China, Imperial Russia, Japan, and the Soviet Union between 1894 and 1945. 
Question : What military branch did William C. Arthur belong to?
Output (English): military branch