In this task, you are given a multiple-choice question and you have to pick the correct option. Answer with option indexes (i.e., "A", "B", "C", and "D").
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Question: What is a source of oxygen through photosynthesis? (A) lakes (B) car engines (C) sunflowers (D) people

Answer: C


Question: Which of the following would have best aided a vessel at sea in crossing the sea in the 18th century? (A) A radar system (B) An old soothsayer (C) An experienced navigator (D) A crow's nest

Answer: C


Question: What is the ultimate source of greeting cards? (A) deserts (B) waterfalls (C) forests (D) canyons

Answer:
C