The diagram illustrates a combination of resistors connected in series and parallel. Which equation is used to calculate the total resistance of the resistors?
- A$R_1 + \frac{R_2 + R_3}{R_2 \times R_3}$
- B$R_1 + \frac{R_2 \times R_3}{R_2 + R_3}$
- C$R_1 + \frac{1}{R_2 + R_3}$
- D$R_1 \times \frac{R_2 + R_3}{R_2 \times R_3}$