Answer:
The religion would the Chinese have come into contact with between 600-1450 Based on the information presented in this passage is Islam (D)
Explanation:
As it can be interpreted from the excerpt that it talks about Arab caliphate which is middle eastern and is part of Islamic rulers or Muslim rulers which was highly prevalent during the period 600-1450 as we know that Islam originated with the birth of Muhammad in 610, the prophet during the beginning of 7 century.
This is close to the period of the excerpt and the terminology that has been used such as the sultan or Khalifa empire makes it self-explanatory that the religion, Chinese came in contact with was Islam.