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%.

Which of the following occurs in the conductors of the preceding problem during the brownout?
a. Both the electric field and electron drift speed decrease.
b. The electric field decreases but the electron drift speed doesn’t.
c. The current is carried by fewer electrons.
d. The electrons undergo more frequent collisions.