Final answer:
Legitimate caliphs in Shia Islam had to be descended from Ali, who was Muhammad's cousin and son-in-law and is considered by Shias as the first rightful caliph. So, the correct answer is option c
Step-by-step explanation:
Legitimate caliphs in Shia Islam are believed to be the descendants of Ali, who was the prophet Muhammad's cousin and son-in-law. Ali is seen as the first rightful caliph by Shia Muslims, as they believe that the leadership of the Muslim community should remain within the Prophet Muhammad's family. After the death of Muhammad, there was a division in the Islamic community with some supporting Ali's immediate right to be the caliph, while others, who came to be known as Sunnis, supported the caliphate of Abu Bakr, Umar, and Uthman before Ali became the fourth caliph.
The division between Sunni and Shia Islam solidified after Ali's death. The Shia held that only Ali and his descendants could be legitimate leaders, a belief that eventually led to the formation of different branches of Shia Islam, with the largest populations today in Iran, Iraq, and Bahrain.
So, the correct answer is option c.