C: had seen Islamic influence driven from the region by the joint French-Dutch “light” campaign
Answer:
Suitable climate and strong military.
Explanation:
Suitable climate of the region motivated Turkish people to expand so far from their original homeland. Turkish people needs suitable environment where vegetation is present for their animals which is limited in their former homeland. They were so successful in creating new states because of their strong military and bravery, the enemies were defeated and the Turks capturing new states.
The answer is approval of conventions in three-fourths of the states.