Answer:
Thermopile is an electronic device that converts thermal energy into electrical energy.
A Peltier cooler, heater, or thermoelectric heat pump is a solid-state active heat pump which transfers heat from one side of the device to the other, with consumption of electrical energy, depending on the direction of the current.
The correct answer is B, widespread pollution. If you look closely, you can see that the other answers are not problems at all, but benefits! :)