13. Which of the following statements provides evidence that magnets aretwo-sided?

a. Magnets contain tiny magnets inside them, each with a North Pole and a South Pole.

b. One end of a magnet attracts one end of second magnet and repels the other end of the second magnet.

c. An unrubbed nail is attracted to either end of a magnet-rubbed nail.

Statements b and c

Statements a, b, and c

Statement a

Statement c

Statement b