The formula for electrical power (P, in watts) is where V is the voltage in volts and R is the resistance in ohms. For a particular brand of water heater, R is 32 ohms and P is 0.5 watts. The formula to find V is , and the voltage at which the heater operates is? (in volts)

A. 16 volts
B. 5 volts
C. 4 volts