题目内容：
阅读以上文章，回答题
What was the significance of the UFO sighting in 1947 according to the passage?__________.
A It was the first evidence showing the existence of intelligent life outside Earth.
B It helped to explain some sightings of unusual events occurring in the sky.
C It aroused widespread interest in unidentified flying objects in the sky.
D It started off a new era of flying saucers in the United States.
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