| List - I | List - II | ||
| (A) | Lungs | (I) | Birds |
| (B) | Gills | (II) | Insects centipedes |
| (C) | Trachea | (III) | Fish |
| (D) | Airsacs | (IV) | Mammals |
Three friends, P, Q, and R, are solving a puzzle with statements:
(i) If P is a knight, Q is a knave.
(ii) If Q is a knight, R is a spy.
(iii) If R is a knight, P is a knave. Knights always tell the truth, knaves always lie, and spies sometimes tell the truth. If each friend is either a knight, knave, or spy, who is the knight?