You did not provide the lines, however, imagery is often used when the writer wants to create a visual image in the minds of his/her reader. It usually consists of numerous descriptions that are often vivid and colorful and highly detailed. You can use that logic on the lines that you might have and see what the correct answer is.
A because in the excert he says yet he wouldnt sleep and his thoughts are restraining him
Answer:
bridge.. it must be the answer to the question..