Critical Reasoning

Brand Zzzoom released a running shoe with a shock-absorbing sole developed using a new foam polymer that reduces muscle fatigue in the legs of runners. The density of the foam, however, results in the overall shoe weight being slightly heavier than most high quality running shoes. Professional runners who welcome the use of Zzzoom's new shoe will definitely experience an improved performance in their runs.

Which of the following, if true, most seriously strengthens the argument?

A) The overall shoe weight is affected not only by the density of the sole but also by the materials used in the other components of the shoe.

B) Since the muscles lifting the leg also lift the shoe, a lighter shoe is likely to produce better results than a heavier one.

C) Research shows that 72% of a runner's muscular energy is expired on impact with the running surface.

D) Too light a running shoe can result in the emergence of knee problems during old age.

E) Aerodynamics can be critical in the optimization of a professional running shoe's performance.

OA C

Source: Economist Gmat