To weaken the conclusion, we have to look for an option that states that installation of cable car will not result in deterioration.

A. The daily number of tourists that are expected to take the cable car to Machu Piccu is smaller than the original resident population of Incas. We don't know how many tourists will cause the destruction of site.

B. The construction of the cable car terminal at Machu Picchu will require the use of potentially damaging heavy machinery at the site. It supports the conclusion.

C. Machu Picchu is already one of the most popular tourist sites in Peru. We are looking for an option that addresses damage to the site.

D. Natural weathering will continue to be a more significant cause of the deterioration of Machu Picchu than tourist traffic. we want to knoe if cable car will cause more destruction.

E. The cable car will replace the tour buses whose large wheels and corrosive exhaust at present do significant damage to the site. This means cable cars will infact be less damaging to the site. Correct answer