If you were asked to describe metals and magnetism you could say
a. non–paired electrons spin in opposite directions in all metals, creating a magnetic field.
b. metals are magnets because they have more electrons than non–magnetic materials.
c. metals can become magnetic if they have many spinning electrons that create magnetic fields.
d. the electrons in some metals pair up to create a magnetic field.

d. the electrons in some metals pair up to create a magnetic field.

Explanation:

Magnetism is the property of attraction and repulsion of certain metals and magnets, which have a positive and a negative pole, characterized by “dipole forces”. When magnetism occurs the electrons in some metals come together to create a magnetic field. The Magnetic Field, in turn, is the concentration of magnetism that is created around a magnetic charge in a given space.

It is the electrons of metals that create the magnetic field, just as it is the electric charge and mass that respectively create the electric and gravitational fields.

b.transmitters send radio waves, and receivers capture radio waves.

co2reflects heat radiation back to earth buning coal and oil emits co2 globe warms