All of the following were reasons for American intervention in World War I by 1917 except ___________.
A. The interception of the Zimmerman telegram
B. The resumption of unrestricted submarine warfare by Germany in 1917
C. A British luxury liner named the Lusitania was sunk by a U-boat, killing 1,198 passengers – including 128 Americans – in May 1915
D. The Ottoman Turks ended up siding with Imperial Germany