Final answer:
The influence of trade and cultural exchange was one specific reason Hinduism was widely accepted in Southeast Asia and the Indonesian archipelago from 1250 CE - 1450 CE.
Step-by-step explanation:
One specific reason Hinduism was widely accepted in Southeast Asia and the Indonesian archipelago from 1250 CE - 1450 CE was the influence of trade and cultural exchange. Through trade, Southeast Asians came into contact with Indian elites and literate Buddhists who became advisers, teachers, and founders of temples across the region. The temples served as critical hubs for travel, learning, and commerce, promoting the spread of Hinduism. Additionally, Indian merchants and missionaries were welcomed in kingdoms, such as Srivijaya, fostering trade relations and the patronization of Buddhism.