将三个均匀的、六面分别标有1、2、3、4、5、6的正方体同时掷出，最上面出现的数字分别为a、b、c，则a、b、c正好是某直角三角形三边长的概率是（　　）。

A、<img width="32" height="41" src="http://admintk.100xuexi.com/UpLoadImage/2016-08-23/33aa0544-62ac-4b9b-b65f-3f8d3c2d1940.png" />

B、<img width="23" height="41" src="http://admintk.100xuexi.com/UpLoadImage/2016-08-23/80d6a94f-4d58-4e82-9ac7-12a3961ca09b.png" />

C、<img width="23" height="41" src="http://admintk.100xuexi.com/UpLoadImage/2016-08-23/75711dd9-d6ed-4004-b252-a515f519c4b3.png" />

D、<img width="21" height="41" src="http://admintk.100xuexi.com/UpLoadImage/2016-08-23/fccd5581-88a9-4e34-b60a-a06e6ffe6503.png" />

A、<img width="32" height="41" src="http://admintk.100xuexi.com/UpLoadImage/2016-08-19/8a30aabe-5112-4789-bfa5-f057fb5fc58c.png" />

B、<img width="23" height="41" src="http://admintk.100xuexi.com/UpLoadImage/2016-08-19/c01a232d-1318-44ca-8d03-330de6dd5a1a.png" />

C、<img width="23" height="41" src="http://admintk.100xuexi.com/UpLoadImage/2016-08-19/d00843c1-12f7-4aae-9628-0b70f65917a2.png" />

D、<img width="21" height="41" src="http://admintk.100xuexi.com/UpLoadImage/2016-08-19/95385d95-8959-4911-8868-2948b4c3496d.png" />