A brownout occurs when an electric utility can’t supply enough power to meet demand. Rather than cut off some customers completely, the utility reduces the voltage across its system. Brownouts are most likely on hot summer days, when heavy air-conditioning loads drive up demand for electricity. In a particular brownout, the utility reduces the voltage by 10%.

During the brownout, the power dissipated in conductors whose resistance is nearly independent of temperature 
a. decreases by approximately 10%.
b. decreases by approximately 20%.
c. decreases by approximately 5%.
d. You can’t tell without knowing the resistance.