Understanding Black-Scholes Components

In the context of the Black-Scholes Model, consider a European call option on a non-dividend paying stock. The relevant variables in the Black-Scholes formula include the stock price (S), the strike price (K), the risk-free interest rate (r), the time to expiration (T), and the volatility of the stock (σ).

Which of the following statements about the components of the Black-Scholes Model is correct?