Answer: b. The words of Vishnu
Step-by-step explanation:
The other options, a. Pax Romana, c. Roads, and d. Christianity's appeal, all played a role in the spread of Christianity.
The Pax Romana, or Roman Peace, was a time of relative peace and stability in the Roman Empire that lasted from 27 BCE to 180 CE. During this time, the Roman Empire had a well-developed system of roads, which made it easier for people to travel and trade. This facilitated the spread of Christianity, as it allowed Christian missionaries to travel and spread the religion to new areas.