Answer:
The correct answer is B, <em>they struggled for control of the Middle East</em>.
Explanation:
The history of the relationship between the Ottomans and Safavids is mainly characterized by their conflicts for the control of different regions of the Middle East. All the other options don't correctly describe this history.
However, because both societies were Muslim according to Islam they couldn't war against each other unless it was for religious reasons.
Thus in the early 1500s Selim I, sultan of the Ottoman Empire consulted his scholars and decided that the Shah Ismail of the Safavids preached heresies against Islam. He then persecuted internal supporters of the Safavids which intensified the rivalry between the two empires.
The conflict between Ottomans and Safavids was fought also through trade embargoes in the 1500s. Ottomans imposed trade embargoes against the Safavids but they only worked until the early 1600s. In the 18th century, they would start to see themselves all parts of the same faith but still fearing each other.
