从四个选项中选择最合适的一个填入问号处，使之呈现一定的规律性：

A、<img src="http://admintk.100xuexi.com/UpLoadImage/2013-05-07/6101484b-a284-4521-9856-7aef568a2ab5.png" width="49" height="46">

B、<img src="http://admintk.100xuexi.com/UpLoadImage/2013-05-07/2525e03d-e4e3-4fbb-b8e3-f5e15673c513.png" width="47" height="45">

C、<img src="http://admintk.100xuexi.com/UpLoadImage/2013-05-07/2c074f86-e5f8-46c0-86de-2d18fc5f11f9.png" width="50" height="47">

D、<img src="http://admintk.100xuexi.com/UpLoadImage/2013-05-07/64a17a15-ff5c-4a54-9e45-8ce50a9b1349.png" width="48" height="47">