在区间[0，1]内随机取出两个数，则这两个数的平方和也在区间[0，1]内的概率是（　　）。

A、<img width="13" height="36" src="http://admintk.100xuexi.com/UpLoadImage/2016-08-19/15c86cdf-6b35-4220-96eb-7b5e8a3a487a.png" />

B、<img width="13" height="36" src="http://admintk.100xuexi.com/UpLoadImage/2016-08-19/5a263b67-7abc-4139-ba76-f8ab42e8fce1.png" />

C、<img width="15" height="36" src="http://admintk.100xuexi.com/UpLoadImage/2016-08-19/eab621b3-c5bd-4eaa-b079-8a36b07ef0b3.png" />

D、<img width="13" height="36" src="http://admintk.100xuexi.com/UpLoadImage/2016-08-19/c807c690-e385-4a59-b8ac-40fb91476f98.png" />