The correct explanation of the three-way trade system that developed after the British Empire took over India is:
The British Empire bought tea from China. In exchange, it sold China opium and cotton the empire had taken from India.
In this system, the British would export opium, which they cultivated in India, to China, where it was in high demand. In return, they would import tea from China, which was highly valued in Britain. This trade system significantly influenced the economies and societies of all involved countries.