GWD SC 题不懂，求助！

Studying the fruit fly, a household nuisance but a time-honored experimental
subject, has enabled the secrets of how embryos develop to begin to be
unraveled by scientists,

A  Studying the fruit fly, a household nuisance but a time-honored experi-mental subject, has enabled the secrets of how embryos develop to begin to be unraveled by scientists.

B.By the study of the fruit fly, a household nuisance and also a time-honored experimental subject, it was possible for the secrets of how embryos develo0p to begin to be unraveled by scientists.

C .By studying a household nuisance but a time-honored experimental sub-ject, the fruit fly enabled scientists to begin to unravel the secrets of how embryos develop.

D .By studying the fruit fly, a household nuisance and also a time-honored experimental subject, the secrets of how embryos develop are begin-ning to be unraveled by scientists.

E. The study of the fruit fly, a household nuisance but a time-honored exper-imental subject, has enabled scientists to begin to unravel the secrets of how embryos develop.
我选的A,答案是E，认为E中enable的发起者可以是subject或The study of the fruit fly。所以觉得E不对，求NN解释，为何选E!谢谢！