The article examines how the Black & Scholes model performs in pricing stock options in a world where interest rates are unpredictable. It assumes a specific model by Jarrows and Merton to be accurate. The study looks at two common ways to estimate the volatility parameter in the model and provides formulas to determine if options are priced correctly. The research shows that sometimes the Black & Scholes model can misprice options, even for short-term ones.