Final answer:
When a metal object is moved from four feet to two feet away from a magnet, the magnetic flux through the object becomes four times as strong, which corresponds to the inverse square law relating distance and field strength.
Step-by-step explanation:
When a metal object is moved two feet closer to a magnet from its original position four feet away, the magnetic flux through the object will increase. The relationship between the distance from the magnet and the strength of the magnetic field is an inverse square law. Therefore, if you halve the distance to the magnet (from 4 feet to 2 feet), the strength of the magnetic field, and hence the magnetic flux, quadruples. So the correct answer to what happens to the magnetic flux when the object is moved two feet closer to the magnet is: C. The flux will be four times as strong.
The magnetic field does indeed decrease rapidly in strength with distance from the magnet, which is consistent with personal experiences with magnets. Just like the electric field lines between a pair of equal and opposite charges, magnetic field lines closer to the magnet are denser, indicating a stronger field.