gmat prep 一模考题 求教

 Less than 35 years after the release of African honeybees outside Sao Paulo, Brazil, their descendants, popularly konwn as kill bees, had migrated as far north as southern Texas.

A. ...

C.  In less than the 35 years since African honeybees had been released outside Sao Paulo, Brazil,

答案就是A，但是我不明白 为什么是A   less than 35 years after ...

请nn指教一下吧    谢谢

我选了C,因为它有 in，虽然后来也是觉得 in less than the 35 years是怪怪的，那个the，说不上来 

自己顶，等待有人来指点迷津 

C中过去完成时态没有道理， 因为主句已经过去完成时态。 Less than 35 years after the release of African honeybees outside Sao Paulo, Brazil, 作为整体修饰主句动词，是过去的某个时间。

嗯，c since的从句里面还带现在完成时，是也蛮怪的，

围绕A选项，如果还原的话，我就是老觉得少了一个介词

Their descendants, popularly konwn as kill bees, had migrated (in) less than 35 years after the release of African honeybees outside Sao Paulo, Brazil, as far north as southern Texas.

谢谢指点