Which window is heated by ESS power only?

The correct answer indicates that the left side window is heated exclusively by ESS (Energy Storage System) power. This means that in systems designed for energy management and efficiency, the left side window utilizes power drawn from the vehicle’s Energy Storage System rather than relying on traditional engine power sources. This setup is particularly beneficial in electric or hybrid vehicles where efficiency in energy use is paramount.

The other options imply that additional windows, such as the right side window, both windshields, or the rear window, are heated without emphasizing the restriction to ESS power. Typically, in many vehicle designs, some windows might have separate heating systems that can operate independently from the ESS. The focus on the left side window as being specifically designated for ESS heat implies a design choice aimed at enhancing energy efficiency, reducing load on the engine, and possibly extending the range of the vehicle by using stored energy where feasible.