Answer:
D
Explanation:
D. He overthrew the sultan and established a Turkish republic.
Mustafa Kemal, later known as Atatürk, played a crucial role in the history of Turkey by leading the Turkish War of Independence and subsequently establishing the Republic of Turkey in 1923. He abolished the Ottoman Sultanate, implemented a series of reforms, and modernized Turkey's political, social, and economic systems. Atatürk aimed to transform Turkey into a secular, democratic, and Western-oriented state, distancing it from the previous Ottoman Empire's political and social structures.