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.


OA E

Please explain the role of HAD in OA.

Past perfect tense involves two actions taking place in the past with one action taking place before the other. I think HAD should be used before exhaled, because exhaled occur before raised. Please correct me if I am wrong.

Thanks,

Kavin