A Chinese investor wishes to acquire a 1-year European-style currency option to purchase USD. The current exchange rate is CNY 6.7355 per USD. A currency trader uses a two-step binomial tree model to price this option. The following details are provided:

• Option expiration time: 12 months
• Option strike price: CNY 6.8665 per USD
• China's annual continuously compounded risk-free interest rate: 1.75%
• US's annual continuously compounded risk-free interest rate: 3.25%
• Exchange rate increase factor: 1.0582
• Exchange rate decrease factor: 0.9450

Determine the value of the option to purchase one USD, given the current spot exchange rate.