The Umayyad clan ruled the Muslim world after the last Rashidun Caliph was killed in 661 AD.

The answer is "Ali"

Explanation:

The Umayyad Dynasty (661-750 CE), the first dynasty to take the title of Caliphate, was established in 661 CE by Muawiya (l. c. 602-680 CE), who had served as the governor of Syria under the Rashidun Caliphate, after the death of the fourth caliph, Ali in 661 CE.

the answer is true!                                          

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