I'm confused about which number is the stock price and which number is the exercise price for binomial option pricing model. Could you please help me distinguish S0 and K?

3. A European call option on a financial asset has strike price $8, while the underlying asset is priced at $9. Consider a three-step binomial tree in which at each step, the price either increases 6% or decreases 6%. Assume that the continuously compounded risk-free rate is 3% per annum and the time step is 8t = = 0.25 year, so that one dollar increases in value to exp(0.03 x 0.25) dollars after one time step