GMAT OFFICIAL GUIDE 12th
Q6. In late 1997, the chambers inside the pyramid of the Pharaoh Menkaure at Gaza were closed to visitors for cleaning and repair " due to moisture exhaled by the tourists, which raised its humidity to such levels so that salt from the stone was crystallizing" and fungus was growing on the walls.
A. because moisture exhaled by tourists had raised the humidity within them
to such levels that salt from the stone was crystallizing.
Can anyone please explain why this choice has been picked by GMAT as the right answer? Cause to me THEM in the sentence could either refer to tourists or chambers and make the sentence not clear.