Question

what led to the division of islam into sunni and shia?
conflict over who should be the caliph
dispute over the meaning of jihad
warfare between the umayyad and abbasid dynasties
warfare between persians and turks

Explanation:

The division of Islam into Sunni and Shia was mainly due to a conflict over the leadership (caliph) after the death of Prophet Muhammad. Sunnis believed the caliph should be chosen by the community's consensus, while Shias thought it should be from the Prophet's family (specifically Ali, his cousin and son - in - law).
The dispute over the meaning of jihad (which is more about spiritual struggle and legitimate military defense in Islamic teachings) is not the root cause of the Sunni - Shia split.
The warfare between the Umayyad and Abbasid dynasties was a later political power struggle within Islamic caliphates and not the cause of the initial Sunni - Shia division.
The warfare between Persians and Turks is a geopolitical and ethnic - based conflict in the Islamic world's history but not related to the Sunni - Shia schism.

Answer:

conflict over who should be the caliph