Pick up the correct statement from the following:

• Permeability is a measure of conducting the magnetic lines of force in the material.
• Permeability is a measure of the extent to which magnetic lines of force can penetrate a medium.
• Permeability is expressed as the ratio of the magnetic flux density (B) to the field strength of the magnetizing field.
• The force between the magnetic poles is inversely proportional to the permeability of the medium.
• All of these