Answer:
A
Explanation:
Coal is majorly used to produces electricity. The coal is ignited and the heat produced used to heat water to steam. The steam is then used to drive turbines with a dynamo effect to produce electricity. Turning off lights when not in use reduces the demand for electricity hence reducing the amount of coal needed to meet this demand.
Other ways to conserve energy is using bulbs with low energy demand - such as LEDs - and improving natural lighting indoors.
