求助：Prep-sc1-84 一道语法盲点，请求帮助！

176. The Nobel Prize in chemistry was awarded to three scientists for their discovery that plastic can be made electrically conductive—an advance that has led to improvements in film, television screens, and windows.

A. that plastic can be made electrically conductive—an advance that has led

B. that plastic can be made electrically conductive—this advance leading

C. that plastic can be made to be electrically conductive, and this advance led

D. of plastic's ability to be made electrically conductive, with this advance leading

E. of plastic being able to be made electrically conductive—an advance that has led

看到PREP笔记中对此题总结好像很模糊。我选B，正确答案是A. 请问B为什么错？

- 是错在an advance和this advance的区别？

- 还是从句与现在分词的区别：可新东方老师讲分词优于从句。

- 难道破折号有什么特别的用法？

是时态，has led表示现在已经完成，leading表示现在正在变