Final answer:
The surroundings have become more constrictive after the narrator's awakening, making the room smaller and increasing the sense of claustrophobia.
Step-by-step explanation:
After the narrator awakens for the second time in 'The Pit and the Pendulum', his surroundings have changed significantly. The correct answer to the question is b) The room has become smaller. This particular detail adds to the growing sense of terror and claustrophobia as the story progresses and the narrator’s situation becomes increasingly dire. The other options are incorrect based on the text provided, and they do not reflect the changes that occur after the narrator's second awakening.