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 data refer to a section of base line measured by a tape hung in catenary.<image 1>Length of tape between 0 and 30 m graduations when horizontal at 20°C and under 5 kg tension is 29.9988 m; cross-sectional area of tape = 2.68 $mm^{2}^$; tension used in the field = 10 kg; temperature coefficient of expansion of tape = $11.16 * 10^{-6}$ per °C; elastic modulus for material of tape = $20.4 * 10^{4} N/mm^{2}$; weight of tape per metre length = 0.02 kg; mean radius of the Earth = $6.4*10^{6}$ m.Calculate the corrected length of this section of the line.
A. 150.507 m
B. 152.507 m
C. 153.507 m
D. 151.507 m

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
A
The following data refer to a section of base line measured by a tape hung in catenary.<image 1>Length of tape between 0 and 30 m graduations when horizontal at 20°C and under 5 kg tension is 29.9988 m; cross-sectional area of tape = 2.68 $mm^{2}^$; tension used in the field = 10 kg; temperature coefficient of expansion of tape = $11.16 * 10^{-6}$ per °C; elastic modulus for material of tape = $20.4 * 10^{4} N/mm^{2}$; weight of tape per metre length = 0.02 kg; mean radius of the Earth = $6.4*10^{6}$ m.Calculate the corrected length of this section of the line.
A. 150.507 m
B. 152.507 m
C. 153.507 m
D. 151.507 m

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.
val