The man was woken at midnight by a fire. Thick smoke in the corridor made him lose his bearings, so he overshot the stairs and entered a different room. So the smoke is why he ended up in another room, option (b). Not finding the stairway is the result of the smoke, not the reason. Nervousness is not mentioned, and he picked up the bundle only after he was in the room, so it cannot be why he went in.
Why each option is right or wrong
(a) Wrong. He missed the stairway because of the smoke; not knowing where it was is the result, not the reason.
(b) Right. The smoke-filled passage made him lose his way and enter another room.
(c) Wrong. Nervousness is not mentioned.
(d) Wrong. He found the bundle only after entering the room.
Answer: UPSC’s key. Explanation: written by UPSC Grade, not by UPSC.
