Which of these played the largest role in buddhism's spread throughout asia from the 100s to the 700s ce?
a. the crusades
b. the silk road
c. mongol invasions
d. persian missionaries

Correct answer choice is :

B) Silk road

Explanation:

Buddhism is the world's fourth biggest religion with over 520 million adherents, or over 7% of the global community, known as Buddhists. An Indian religion, Buddhism includes a diversity of cultures, faiths and religious modes mostly based on primary education connected to the Buddha and ending defined theories. Buddhism began in Ancient India as a Sramana myth sometime between the 6th and 4th centuries BCE, increasing through much of Asia. Two main existing branches of Buddhism are commonly acknowledged by scholars.

b. the silk road  

Explanation:

Buddhism entered Han China by means of the Silk Road, starting in the first or second century CE.  

The first recorded interpretation endeavors by Buddhist priests in China (all outsiders) were in the second century CE affected by the extension of the Kushan Empire into the Chinese domain of the Tarim Basin under Kanishka.  

These contacts brought Gandharan Buddhist culture into regions neighboring China proper.

your answer would be just capitalism.