The correct answer are:
A. Persian traditions strongly affected the caliphate.
In the mid-8th century, the Abbasid Caliphate succeeded to the Arab Omayyad Caliphate, which was based in Damascus, after many Persians and other non-Arabs rebelled against the Arab rulers and established the new Caliphate with its new capital in Baghdad. This new Islamic Empire was strongly influenced by Persian culture and traditions, to the fact that most of its administration, bureaucracy, and military was in the hands of Persian officers.
B. Major campaigns made the military a more dominant class.
The strength of the Abbasid Caliphate was based to a great extent in the capacity of its military power since they took power from the Omayyad dynasty due to military force. Later, they needed to ensure their power struggling with internal and external threats.
E. Non-Arab Muslims were allowed to hold powerful positions.
In the Omayyad Caliphate, non-Arab Muslims were considered second-class citizens while Arab Muslim were first-class citizens. This was due to the fact that the Omayyad Caliphate was basically an Arab Empire. Since the new Abbasid empire was created mainly by non-Arab Muslims (Persian, Kurdish, Turks), the Caliphate turned into a multicultural and multi-ethnic empire and many times the new power was in the hands of Non-Arab Muslim authorities.