Final answer:
Missionaries played a crucial role in the spread of Buddhism in India, Sri Lanka, and Central Asia.
Step-by-step explanation:
In India, Sri Lanka, and Central Asia, missionaries played a significant role in spreading Buddhism. They helped to disseminate the teachings of Buddhism, establish temples, and promote the faith to local populations.
For example, in India, King Ashoka was an early sponsor of Buddhism and used his power to propagate the religion. In Sri Lanka, missionaries, including Ashoka's son, played a vital role in the adoption and growth of Buddhism.
Similarly, in Central Asia, trade and diplomatic relations facilitated the spread of Buddhism by allowing the exchange of ideas, practices, and art between different regions.