---Do you like his joke?---Not at all. ______

--- Do you like his joke?
--- Not at all. ________.A.It’s full of humor.B.It’s too interesting.C.It’s too obvious.D.It’s really silly.

D解析考查单词，humor幽默，interesting 有趣；obvious 易解的；silly 无聊的；根据句意一点儿也不喜欢，真的很无聊。故选D.

谢谢了