Answer:
The “topless towers of Ilium” were believed to be indestructible, but Helen led to their ruination; this parallels Faustus’s downfall.
Step-by-step explanation:
This is the sentence that best describes the effect of the excerpt below. In this passage, the "topless towers of Ilium" refers to something that was meant to be powerful and indestructible. However, Helen and her sins led to their ruination. Helen is used as an analogy to Faustus's own tragic journey. Just like Helen, Faustus is pursuing a goal driven by sinful wishes. And just like Helen, this is likely to lead to his downfall.