A magnet can hold a piece of paper to the door of a refrigerator. How does the magnet stick without touching the door?
a
The magnetic field of the magnet can act at a distance, and influence the metal of the door through the paper.
b
The magnet induces a magnetic field in the paper.
c
Friction attracts the paper to the magnet.
d
Gravity attracts the magnet to the door.