The event that created the strongest motivation for groups in the Middle East to seek land to create their own nation-states is C. a push for nationalism.
Nationalism, particularly in the 20th century, was a significant driving force behind the desire for self-determination and the establishment of nation-states in the Middle East. Various groups sought to define their national identity and secure land for their own nations, often in response to colonial rule and the artificial borders imposed by external powers. While the other options may have contributed to political dynamics in the region, nationalism is the most central factor in the context of seeking nation-states.