求助，Prep里since的问题

yuyang0206

3.(24557-!-item-!-188;#058&001027)

Less than 35 years after the release of African honeybees outside Sao Paulo, Brazil, their

descendants, popularly known as killer bees, had migrated as far north as southern Texas.

(A) Less than 35 years after the release of African honeybees outside Sao Paulo, Brazil

,

(B) In less than 35 years since releasing African honeybees outside Sao Paulo, Brazil

,

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

Brazil

,

(D) It took less than 35 years from the release of African honeybees outside Sao Paulo, Brazil

,

when

(E) It took less than the 35 years after the time that African honeybees were released outside

Sao Paulo, Brazil

, and then
我就看到语法解释里说，C的since不符合用法？但是since 后面可以加从句啊，Africa honeybee had been 就是把
然后还有个问题，是LESS THAN, MORE THAN在句首不用考虑逻辑主语问题？是不是只有doing, done, 介词，adi在句首才考虑逻辑主语问题啊？
谢谢~