What stays with you is the part of your education.

网友理解正确，答案错误。没有定语 of your education，哪来的 part？定语和中心词是不可分割的。

我不知你这句来源是什么，但这句话本来意思就不对，犯了“句意不明”的毛病。

What stays with you is the part of your education.

这句话意思根本不完整。读者的兴趣焦点在the part上面？到底是什么part？可原句戛然而止。

我们不妨补充些信息

What stays with you is the part of your education taken abroad. 

What stays with you is the part of your education that promotes personal development.