Explanation

Mustafa Kemal Atatürk is correct because he was the leader who issued decrees regarding the Hagia Sophia's status. Abdulhalik Renda is incorrect as he was not the person who issued this specific decree. Abdullah Gul is incorrect because he was not responsible for transforming the building into a museum. Recep Tayyip Erdogan is incorrect because he was not the first president to issue that particular decree.