设A={{1,2,3},{4,5},{6,7,8}},下列选项正确的是( )
②
{1,2,3}<imgwidth="15"height="15"src="../uploadfiles/word/lsss002.files/image038.png">A
③
{{4,5}}<imgwidth="15"height="12"src="../uploadfiles/word/lsss002.files/image039.png">A
④
<imgwidth="16"height="17"src="../uploadfiles/word/lsss002.files/image040.png">∈A