The most accurate response to analyze why the Umayyad Empire ended in 750 is:
Discontent amongst non-Arab Muslim converts weakened the empire.
The Umayyad dynasty faced significant internal strife, particularly from non-Arab Muslims (known as Mawali), who felt marginalized and discriminated against within the empire. This discontent was a key factor that contributed to the rise of the Abbasid revolution, which ultimately led to the overthrow of the Umayyads in 750. The Abbasids were able to galvanize support among various groups, particularly those dissatisfied with Umayyad rule, and this internal dissent was a critical factor in the empire's collapse.