A .first of all ,首先,首先,欢迎你来我们学校.
at all 根本 at first 起初,最先 She didn't like English at first.
after all 毕竟 终究
故选A.
希望可以帮助你哦 !A与C的区别是什么，首先....... 其次.......最后.......这样的句子用哪个First or all/ firstly.... secondly.... at last 祝你学习进步！at first 起初，最先， 不表次序的