小样本情况下，总体服从正态分布，总体方差未知，总体均值在置信水平（1-α）下的置信区间为（　　）。

A、<img src="http://admintk.100xuexi.com/UpLoadImage/2013-05-07/c619739d-7fba-4e4b-a165-55c8b67ccd88.jpg" width="165" height="40" />

B、<img src="http://admintk.100xuexi.com/UpLoadImage/2013-05-07/e73cf37b-3402-41e1-9d8b-429705374e89.jpg" width="136" height="42" />

C、<img src="http://admintk.100xuexi.com/UpLoadImage/2013-05-07/c682f234-8b3c-418d-8f87-fa5989e51e16.jpg" width="132" height="38" />

D、<img src="http://admintk.100xuexi.com/UpLoadImage/2013-05-07/45907207-64f9-4c91-898a-22cbe0f35243.jpg" width="133" height="41" />

A、<img src='/s/tiw/p3/UpLoadImage/2013-05-07/c619739d-7fba-4e4b-a165-55c8b67ccd88.jpg' width='165' height='40'>

B、<img src='/s/tiw/p3/UpLoadImage/2013-05-07/e73cf37b-3402-41e1-9d8b-429705374e89.jpg' width='136' height='42'>

C、<img src='/s/tiw/p3/UpLoadImage/2013-05-07/c682f234-8b3c-418d-8f87-fa5989e51e16.jpg' width='132' height='38'>

D、<img src='/s/tiw/p3/UpLoadImage/2013-05-07/45907207-64f9-4c91-898a-22cbe0f35243.jpg' width='133' height='41'>