Which question cannot be answered through making measurements? A. Should wolves be reintroduced into national parks?
B. What is the birthrate for wolves in their natural habitats?
O c. How would reintroducing wolves into a national park affect the
deer population there?
D. Which species in a national park do wolves hunt?

The independent variable would be the fertilizer as it is what the dependent variable (the growth of grass) depends on.

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.

It really doesn't matter for any of the questions that you've listed.