I'm pretty sure its A. The collapse of Christianity.
I'm pretty sure it's C: "pointing to the U.S. military presence on Islamic soil" =)
Is this even a question tho ??!!!...
The answer is the Ottoman Empire.
The Ottoman Empire conquered the Byzantine Empire and its capital, Constantinople, in 1453 CE. Since then, the Ottoman Empire remained as a strong power and its sovereignty spanned from the Balkans and Anatolia to the Middle East and all of North-Africa. Since it was an Islamic empire, it influenced strongly in the culture and politics of the Middle East. This empire collapsed with the end of the World War I in 1919, and most of its former territories were divided by the British and the French or formed new nation-states. The Republic of Turkey is the direct heir state of the Ottoman Empire.