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>Using the oxygen affinity curve in <image 1>, determine the amount of oxygen that would be delivered to cells at PO2 = 20 mmHg if the PO2 of the lungs were 60 mmHg. Assume maximum HbO2 to be the level of oxygen delivery if all available oxygen in the RBC's was transferred to cells.
A. 17% of the maximum HbO2 would be delivered.
B. 22% of the maximum HbO2 would be delivered.
C. 65% of the maximum HbO2 would be delivered.
D. 70% of the maximum HbO2 would be delivered.
E. 82% of the maximum HbO2 would be delivered.

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
C
Using the oxygen affinity curve in <image 1>, determine the amount of oxygen that would be delivered to cells at PO2 = 20 mmHg if the PO2 of the lungs were 60 mmHg. Assume maximum HbO2 to be the level of oxygen delivery if all available oxygen in the RBC's was transferred to cells.
A. 17% of the maximum HbO2 would be delivered.
B. 22% of the maximum HbO2 would be delivered.
C. 65% of the maximum HbO2 would be delivered.
D. 70% of the maximum HbO2 would be delivered.
E. 82% of the maximum HbO2 would be delivered.

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