Final answer:
The initial issue that created a division for Muslims into Sunni and Shi'a was who should have the right to leadership after the Prophet Muhammad. option (B)
Step-by-step explanation:
The issue that initially created a source of contention and division for Muslims into Sunni and Shi'a was who should have the right to leadership after the Prophet Muhammad. Some Muslims believed that leadership should come from the Prophet's family, while others believed that it should be open to anyone who was an effective and dynamic leader.
The majority of Muslims, known as Sunnis, believed that leadership should be open to anyone. They accepted the decision that the first leader of the community would be Abu Bakr, the father-in-law of Muhammad. On the other hand, the Shi'ites believed that leadership should be exclusively in the family of Muhammad, particularly through his son-in-law Ali.
This disagreement over leadership led to a schism within the Muslim community, with Sunni and Shi'a Muslims forming distinct sects. While Sunnis make up about 90% of Muslims today, Shi'a Muslims make up about 10%.