Other than Volatility and Time to Expiration, the article missed 3 other very important factors in order to price the GOLD option correctly.
1. Interest rate of the currency to carry the trade (RMB interest rate)
2. The gold spot price (underlying price)
3. The FX rate between RMB and USD (USD is used for quoting GOLD, just as other commodity such as OIL).
Without considering all 5 major factors in this simple vanilla Option, an investor will not make an educated investment decision.
