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.

early settlements on the subcontinent. both the indus and the ganges rivers carried rich silt from the mountains to the plains. when the rivers flooded, the silt spread over the plains and made the soil in the river valleys fertile for farming.