Final answer:
The key dispute separating the Sunni from the Shia is a dispute over Muhammad's successor.
Step-by-step explanation:
The key dispute separating the Sunni from the Shia is a dispute over Muhammad's successor. After the death of the Islamic prophet Muhammad, there was a disagreement about who should lead the Muslim community. The Sunnis believed that leadership should be based on consensus, while the Shias believed that only the descendants of Muhammad should lead.
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