The main function of Nest Thermostat E is to reduce the energy used. It does this by learning your heating and cooling habits and automatically adjusting the temperature to save energy when you’re away. You can also control the thermostat from anywhere using the Nest app, so you can make sure your home is always at the perfect temperature, even when you’re not there.
Option A is incorrect because the Nest Thermostat E can be used to change the temperature even when you’re not at home. Option B is incorrect because the Nest Thermostat E can be used to reduce energy use without changing the temperature. Option C is incorrect because the Nest Thermostat E can be used to change the temperature from anywhere, not just when you’re at home. Option D is incorrect because the Nest Thermostat E does not power off when a person is not present.