The EPA sets national air-quality standards for common air pollutants. The
table shows the change in the concentrations of these pollutants over time
and the impact on overall air quality. Reducing which pollutant resulted in the
most air-quality improvement?

stands for electromotive force and it is measured in volts. despite its name, it is not actually the force in the sense of being a "pushing" or "pulling" (not measured in newtons).an equation that relates emf,  ℰ,  to a battery's terminal voltage, v, current, i, and internal resistance, r, is    ℰ = v + irin this case, the emf can be interpreted as a voltage—a difference in electric potential.i would not say that it would be considered an energy. if emf can be defined as the energy/work per a unit charge from a battery or other electric source, then it is not strictly energy.

Answertechnician (a) is correct;

  the answer is don't know.