In the Black-Scholes Option Pricing Model, the Symbol "σ" Is

In the Black-Scholes option pricing model, the symbol "σ" is used to represent the standard deviation of the:

A) option premium on a call with a specified exercise price.
B) rate of return on the underlying asset.
C) volatility of the risk-free rate of return.
D) rate of return on a risk-free asset.
E) option premium on a put with a specified exercise price.