困惑的语法题

寂寞的自由

6. As Hurricane Hugo approached the Atlantic coast, it increased dramatically in strength, becoming the tenth most intense hurricane to hit the United States mainland in the twentieth century and most intense since Camille in 1969.   B-àC
(A) most intense since Camille in 1969
(B) most intense after Camille in 1969
(C) the most intense since Camille in 1969
(D) the most intense after 1969, which had Camille
(E) since 1969 and Camille, the most intense

请问大家，这个题出题点是什么，我不太明白，正确答案是C，大家如何排除的呢？

寂寞的自由

A，C，E都有SINCE 啊！！！应该主句用完成时态哦！为什么就C正确呢？郁闷！

dreadpower

请规范格式，好吗？？

   请参见这个http://forum.chasedream.com/dispbbs.asp?boardID=23&ID=32446

   谢谢配合