Driving the steep road to the mountaintop Inca ruins of Machu Picchu is potentially dangerous and hiking there is difficult. Now the Peruvian government is installing a cable car that will make access much easier, and hence result in a large increase in tourism. However, since the presence of large numbers of tourists tends to accelerate the deterioration of a site, installation of the cable car is certain to result in harm to the ruins.

Which of the following, if true, most seriously calls into question the argument?

• AThe daily number of tourists that are expected to take the cable car to Machu Piccu is smaller than the original resident population of Incas.  
• BThe construction of the cable car terminal at Machu Picchu will require the use of potentially damaging heavy machinery at the site.  
• CMachu Picchu is already one of the most popular tourist sites in Peru.  
• DNatural weathering will continue to be a more significant cause of the deterioration of Machu Picchu than tourist traffic.  
• EThe cable car will replace the tour buses whose large wheels and corrosive exhaust at present do significant damage to the site.