| List- I I-V Characteristics | List-II Diodes | ||
|---|---|---|---|
| A | ![]() | I | Solar Cell |
| B | ![]() | II | L.E.D |
| C | ![]() | III | Zener diode |
| D | ![]() | IV | Photo diode |

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?