PIMSO 2021 - Science - Grade 6 - National Round Mock Test Question 16

The set-up below is made up of four rings, P, Q, R and S. Based on the information above, which of the following are possible materials for P, Q, R and S?
I: P magnet; Q steel; R magnet; S steel.
II: P magnet; Q iron; R magnet; S magnet.
III: P iron; Q magnet; R magnet; S plastic.
IV: P steel; Q plastic; R iron; S magnet.