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>Choose the word that best describes the geometric shape of the molecule or ion whose Lewis structure is shown below. <image 1>
A. linear
B. bent
C. triangular planar
D. tetrahedral
E. square planar
F. triangular pyramid
G. triangular bipyramid
H. octahedral
I. T-shape

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
Choose the word that best describes the geometric shape of the molecule or ion whose Lewis structure is shown below. <image 1>
A. linear
B. bent
C. triangular planar
D. tetrahedral
E. square planar
F. triangular pyramid
G. triangular bipyramid
H. octahedral
I. T-shape

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