_______ many times, he finally understood it
A.ToldB.TellingC.Having toldD.Having been told在线课程D
解析：
考查非谓语动词。根据句意可知先被告诉许多次，故用现在分词的被动Having been told，表示动作先后性。句意：被告诉了许多次，他最终理解了。