Think about the magnets in terms of energy. In which case do you increase the potential energy of the magnets? In which case do you increase the kinetic energy of the magnets?

Use a more magnetic material

Use more fields

Explanation:

The magnetic energy is a special energy in substances. This is the energy possessed by ferric metals. In other terms, these are metals that have a lot of delocalized electrons. The transition metals are magnetic. The most magnetic metal is iron. The magnetic power of iron is in the domains in the metal. The domains are the movements of the particles in the magnetic field. These correspond to the earths magnetic field. The potential energy can be increased by incorporating electricity. The electricity makes the domains to take a certain direction in the field.

the answer is b & c i believe : )