Final answer:
Exporting silk worms from China was illegal in order to safeguard China's dominance in the silk industry.
Step-by-step explanation:
The correct answer is c) To safeguard China's dominance in the silk industry. Exporting silk worms from China was illegal in order to protect China's dominance in the silk industry. China held a monopoly on silk production for many years, and by keeping the silk worms within the country, they maintained control over the production and quality of silk.