Answer:
Correct answer is B. Ottoman Empire.
Step-by-step explanation:
A is not correct answer as United States were neutral until 1917, when they decided to support the causes of Entente.
B is correct as the Ottomans were fighting with Russia since 17th Century, and especially around Crimea and Balkan Peninsula. Ottomans knew that Russia wanted to capture Constantinople.
C is not correct as Italy, a country that was a part of Central Powers, turned its back on them after signing the London Treaty in 1915.
D is not correct as Netherlands remained neutral during WW1.