由t分布可知,自由度∪越小.t分布的峰越矮,尾部翘得越高,故正确的是

A、[img=~/QImg/2013-10-14-10-49-09/image010.jpg]
B、[img=~/QImg/2013-10-14-10-49-09/image011.jpg]
C、[img=~/QImg/2013-10-14-10-49-09/image012.jpg]
D、[img=~/QImg/2013-10-14-10-49-09/image013.jpg]
E、以上都不对