Some similarities and differences between the Byzantie Empire and Kiev Russia consist of the Byzantie Empire's period lasting from 330-1613, whereas Kiev's period lasted from the 700's-1110's. The Byzantie Empire was a more advanced society then Kiev. Kiev recieved most of their culture from cultural diffusion from Byzantie. Some similarities include that two leaders from both locations converted to Christianity. Both locations were the only ruler. And both locations strived to control the church, also known as to control the people. Supremacy existed in both.
Not sure if you had any answer choices, but through merchants, who traded across the Indian Ocean, Hinduism spread to Southeast Asia, in regions like Vietnam. Buddhism spread along trade routes like the Silk Road. It made its way into East and Southeast Asia in regions like China, Korea and Japan. If you are looking for an area they both spread to it would be Southeast Asia.
To allow American merchant ships to access war zones
The answer is Federalism if you are using Apex