在大样本条件下，若np≥5，且n（1-p）≥5，样本比例在置信水平（1-α）下的置信区间为（　　）。

A、<img src="http://admintk.100xuexi.com/UpLoadImage/2013-05-07/4f2dc21c-ef96-477c-9d42-98947cba849e.jpg" width="277" height="47" />

B、<img src="http://admintk.100xuexi.com/UpLoadImage/2013-05-07/90b2f17e-bfbf-4f24-8f04-5c42fd5171d4.jpg" width="198" height="40" />

C、<img src="http://admintk.100xuexi.com/UpLoadImage/2013-05-07/d3dfa05f-feb1-4c42-8ddb-d7f5694860cb.jpg" width="197" height="42" />

D、<img src="http://admintk.100xuexi.com/UpLoadImage/2013-05-07/d2b2e6d5-66a1-4e0c-af07-c47407cce649.jpg" width="197" height="46" />