Why did Buddhism spread, and why was it widely accepted under the Mauryan Empire?

Siddhartha sent royal officials throughout the Mauryan Empire, and he taxed those who did not covert.

Asoka sent missionaries to other parts of Asia, and he was tolerant of other religions.

The Buddha traveled throughout Asia, and he forced Buddhism on the people of the Mauryan Empire.

The best response is, Asoka sent missionaries to other parts of Asia, and he was tolerant of other religions.

Before converting to Buddhism Asoka was fierce military ruler and conqueror of India. After years of conquests and killing he converted to Buddhism and advocated for the religion among his territories, this included the use of missionaries for conversion. Much of his leadership, including government edicts, focused on tolerance and respect among his people.

The answer is the second choice