What is magnetism caused by?
a. the motion of protons
b. the motion of electrons
c. the attraction between protons and electrons
d. the interaction between neutrons and protons

Magnetism is caused by the motion of electrons. The force exerted by magnets when they attract or repel each other is called Magnetism. Atoms are the tiny units that compose a substance. In each atom there are electrons that carry electric charges. When these charges move in a spinning motion the electrons tend to circle the core of the atom, which is the nucleus. These movements generate electric currents that cause the electron to act like a microscopic magnet hence causing magnetism to occur.  

You not be doing this in a quiz. if you actually studied your work you would know the answer. the answer though is that they would use gdp per capita because it measures a smaller portion (person). this could show individual growth per person in the country.