Answer:
A. Religious differences.
Step-by-step explanation:
According to other sources, these are the options that come with this question:
A. Religious differences.
B. Fighting over limited food sources.
C. Access to oil.
D. Fighting over who would take the throne.
The main reason for the conflict between these two empires was religious differences. The Safavid Empire followed what is known as Shia Islam, while the Ottoman Empire followed Sunni Islam. This was an important aspect of the countries' relation, as Muslims are not allowed to engage in war with other Muslims unless this is a result of religious differences (to enforce a sacred law or to check transgressions against it).