og代词指代问题

dangling

In late 1997, the chambers inside the pyramid of the Pharaoh Menkaure at Giza were closed to visitors for cleaning and repair 【due to moisture exhaled by tourists, which raised its humidity to such levels so that salt from the stone was crystallizing and fungus was growing on the walls.】

　　A. due to moisture exhaled by tourists, which raised its humidity to such levels so that salt from the stone was crystallizing

　　B. due to moisture that tourists had exhaled, thereby raising its humidity to such levels that salt from the stone would crystallize

　　C. because tourists were exhaling moisture, which had raised the humidity within them to levels such that salt from the stone would crystallize

　　D. because of moisture that was exhaled by tourists raising the humidity within them to levels so high as to make the salt from the stone crystallize

　　E. because moisture exhaled by tourists had raised the humidity within them to such levels that salt from the stone was crystallizing

答案解释说CD中的them指代tourists,E中的指代chambers。是不是因为E中tourists在修饰语里？
代词做主语指代是不是应该是优先考虑主语，然后是宾语，表语，最后是修饰里的名词。但是如果像这道题一样them在介词短语里呢？按这个顺序来找先行词，为什么到E选项就不能用tourists了呢？
彻底晕了
先谢谢啦

ukyo2003

我记得OG中是说因为tourist靠them这个代词更近，所以有指代歧义。

dangling

ukyo2003 发表于 2015-3-26 17:05
我记得OG中是说因为tourist靠them这个代词更近，所以有指代歧义。

E中也很近啊，但就不是指代tourists。界限在哪儿呢