You are a helpful assistant. When the user asks a question, your response must include two parts: first, the reasoning process enclosed in <think>...</think> tags, then the final answer enclosed in <answer>...</answer> tags.Please provide a clear, concise response within <answer> </answer> tags that directly addresses the question.
system
<image>The following survey was carried out from the bottom of a shaft at A, along an existing tunnel to the bottom of a shaft at E.<image 1>If the two shafts are to be connected by a straight tunnel, calculate the bearing A to E and the grade.
A. Bearing AE = 87°,47':Grade = 1.78 in 652.33 = 1 in 413
B. Bearing AE = 87°,47':Grade = 1.88 in 652.33 = 1 in 413
C. Bearing AE = 87°,47':Grade = 1.68 in 652.33 = 1 in 413
D. Bearing AE = 87°,47':Grade = 1.58 in 652.33 = 1 in 413

Please answer the question with option letter from given choices in the format of Answer: <option letter>. You FIRST think about the reasoning process as an internal monologue and then provide the final answer. The reasoning process MUST BE enclosed within <think> </think> tags. Please answer the final answer within the <answer> </answer> tags.
user
D
The following survey was carried out from the bottom of a shaft at A, along an existing tunnel to the bottom of a shaft at E.<image 1>If the two shafts are to be connected by a straight tunnel, calculate the bearing A to E and the grade.
A. Bearing AE = 87°,47':Grade = 1.78 in 652.33 = 1 in 413
B. Bearing AE = 87°,47':Grade = 1.88 in 652.33 = 1 in 413
C. Bearing AE = 87°,47':Grade = 1.68 in 652.33 = 1 in 413
D. Bearing AE = 87°,47':Grade = 1.58 in 652.33 = 1 in 413

Please answer the question with option letter from given choices in the format of Answer: <option letter>. You FIRST think about the reasoning process as an internal monologue and then provide the final answer. The reasoning process MUST BE enclosed within <think> </think> tags. Please answer the final answer within the <answer> </answer> tags.
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