Why did most people within the byzantine and persian empires accept islam so easily?
a. they would be allowed to serve in government positions
b. they were concerned about repression by the new muslim government
c. trade opportunities increased and improved their earnings.

Islam is a religion of peace. When they invaded the Byzantine and Persian empires, they were given options to accept Islam and in return, they won't be discriminated in any means, including their role in government. In addition, they were promised to be given all the rights which Islam allows for the Muslims and the other religions as well. Being influenced by the sympathy and equality in Islam, both these nations entered into the religion and played their roles in the government as well.

i dont know the answer sorry but if i knew it i would of told you