Final answer:
Option (a), The empire most closely associated with the events described, including the conquest of Constantinople and conflicts with the Russian Empire, is the Ottoman Empire.
Step-by-step explanation:
The Ottoman Empire and its Significance
The empire most closely associated with the events outlined in the provided information is the Ottoman Empire. This empire's historical influence extends through various significant events, including the conquest of Constantinople by Sultan Mehmed II in 1453 and the long-term conflict and competition with the Russian Empire over the Black Sea and the Balkans. The Ottoman Empire, a Sunni Muslim empire with its homeland in what is present-day Turkey, bordered Orthodox Christian Russia to the north and the Sh_iite Iranians who succeeded the Safavid Empire to the east. During the 19th-century it was often referred to as "the Sick Man of Europe" and managed to persist until its collapse after World War I.
Through centuries of engagement in territorial conflicts, administrative reforms, and interactions with European powers, the Ottoman Empire left an indelible mark on world history. Nation states like Greece, Egypt, and Arabia gained independence from the Empire, which eventually succumbed to internal revolts, European encroachment, and eventually was divided post-World War I. The legacy of the Ottoman state extends beyond its military achievements, influencing the cultural, religious, and economic milieu of its time. Its termination signaled the end of a significant epoch in Islamic and world history.