Correct Answer: B
There are two different proposed causes of tire decay on bikes: (1) "contact between the tire and pavement" (2) "chemicals from the road's composition and chemicals from rain residue" In order to ascertain which theory is correct, we must separate the two proposed causes. This can be done by applying chemicals from rain water and pavement (theory 2) onto a bike's idle tires. It is important that the bike is idle as this rule
out theory 1.
A. This method does not isolate the new and proposed theory for why bike tires wear down as the testing method exposes the tires to both potential causes (i.e.: (1) tire and pavement contact (2) chemicals from the road's composition and rain residue).
B. This method isolates the two competing sources of explanations for the tires' erosion. If the tires erode under this scenario, we know that it was not riding on the pavement that caused the erosion but rather it was the exposure to chemicals.
C. This method does not account for both the potential influence of chemicals from the road's composition and chemicals from rain residue on the surface of the bike tire. Simply because the manufacturer used or did not use chemicals from the road's composition within the bike's frame does not enable us to conclude that the same chemicals will or will not have a corrosive effect if applied to the bike's tires. In other words, testing effects on the bike's frame is entirely unrelated to testing effects on the bike's tires as these two components (i.e., frame and tire) are made of entirely different materials.
D. This method does not account for the potential influence of chemicals from the road's composition and chemicals from rain residue on the surface of the bike tire. Simply because the manufacturer used or did not use rust-resistant components for the bike's frame does not enable us to conclude what effect water may have on the bike's tires. In other words, testing effects on the bike's frame is entirely unrelated to testing effects on the bike's tires as these two components are made of entirely different materials.
E. Without any useful frame of reference (such as the number of miles a tire can be used on a dry road or the number of miles a tire can be used in a grass field without the chemicals of a typical road), it is impossible to make any logical conclusion about whether friction or chemicals are causing the decay of the tire.