【单选题】
下列二阶方阵中可对角化的是()
①
<imgwidth="68"height="58"v:shapes="_x0000_i1241"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds04.files/image307.png">
②
<imgwidth="66"height="58"v:shapes="_x0000_i1242"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds04.files/image309.png">
③
<imgwidth="58"height="58"v:shapes="_x0000_i1243"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds04.files/image311.png">
④
<imgwidth="68"height="58"v:shapes="_x0000_i1244"src="http://wljy.whut.edu.cn/uploadfiles/word/xxds04.files/image313.png">