Answer: A. The connections his family had to the old Ottoman order that preceded him. His role as a military commander during World War I
Explanation:
One of the main factors that helped Mustafa Kemal Atatürk gain popularity before becoming the first president of Turkey was his role as a military commander during World War I. He emerged as a prominent leader during the Turkish War of Independence (1919-1923) when he successfully led the Turkish forces in their fight against foreign occupation and internal resistance. His military victories and leadership in this war earned him immense respect and popularity among the Turkish people, leading to his rise as a significant figure in the country's history.