An unusual Halloween party, an annual event in Boulder, Colorado, is known as the Naked Pumpkin Run, caused trouble.
A. what
B. that
C. it
D. which
网友回答
A. what
B. that
C. it
(答案→)D. which
解析：句意：在科罗拉多州波尔德地区，一年一度的以“南瓜裸奔”而闻名的盛事成为一场异常的万圣节派对，惹上了麻烦。这里是一个非限制性定语从句，故排除A、B和C。