<u>Answer:</u>
The word, if used to replace "quiet," in the given sentence "Then the people went to their beds, and the camp was quiet." would give this sentence a more negative tone is (B) Stifled.
"Then the people went to their beds, and the camp was <u>stifled</u>."
<u>Explanation:</u>
The word "Quiet" literally denotes a place which is void of noise. Here, in the given sentence, when the people who used to camp went back to bed, one should expect a calm and a peaceful atmosphere. During the bed time, no one will make such loud noises which will distract the people in the environment as everyone tend to take rest during night. The word "Quiet" denotes that type of environment too.
The word "Silent" is similar in meaning to the word "Quiet" and it generates a positive tone too. The word "Still" denotes the environment which is undisturbed by any external factors. Hence, the word "Still" also projects the exact nature of the environment. If we use the word "Stifled" in the above sentence, it refers to the environment which is generally constrained from doing something i.e., enforcing an order to do something. Here, the word "Stifled" creates a negative tone when replaced in the given sentence.