Final answer:
The secret method for making silk kept it valuable in classical China.
Step-by-step explanation:
One of the main reasons silk remained highly valuable in classical China was because Chinese artisans kept the method for making it a secret. The art of silk production was highly guarded, and only a limited number of people knew how to produce it. This exclusivity made silk a rare and luxurious commodity, increasing its value in the market.
Learn more about silk production in classical China