Answer: The answer is B. They all have a single international spiritual leader.
Explanation: I'm a Christian
They were both Muslim Empires. they incorporated mystical aspects into Islam that were easily adopted by converts in Asia familiar with Hinduism and Buddhism. the spread of Islam to western African kingdoms such as Songhai.
This sentence technically doesn't contain an error in verb-noun agreement, however the noun "each one" is odd here. It should be "everyone"