Geologist: A geological fault in the mountain under which the proposed nuclear waste storage facility would be buried could, after a few thousand years, cause the contents to seep out or water to seep in. Since nuclear waste remains dangerous for up to 25, 000 years, such seepage would be disastrous. So we should not place a nuclear waste storage facility under this mountain until scientists investigate whether this mountain has any geological faults. Which one of the following arguments, if true, most strengthens the geologist's argumentation? ["The scientists' investigation would conclusively show whether or not the mountain has any geological faults.", 'Nuclear waste could be stored in the proposed facility on a temporary basis.', 'The proposed facility was not initially intended to be used for the storage of nuclear waste.', "The scientists' investigation would increase dramatically the cost of storing nuclear waste under the mountain."]