The standard computer keyboard, called QWERTY because of the arrangeme

The standard computer keyboard, called QWERTY because of the arrangement of the first six letters, is very inefficient. The letters were arranged in this odd but familiar manner when the first typewriters were being designed in the 1800s. When keys were arranged logically, typists could strike the keys very quickly. Early typewriters were so slow the fast typists caused mechanical problems in the machines. In order to slow down the typists, the keys were rearranged in a seemingly random order. If a manufacturer of computer keyboards were to arrange the keys in the most efficient manner, everyone would want to buy a new, improved keyboard.

If true, which of the following would most seriously weaken the above conclusion?

(A) Modern computer word-processing systems are much faster than the most accomplished typist and there is no reason to use the slower keyboard.

(B) Americans have universally adapted to the QWERTY keyboard and aren’t interested in learning an entirely new system.

(C) Discovering the most efficient arrangement of keys would require extensive tests on typists and non-typists alike.

(D) The human brain is incredibly adaptable and can adapt to any arrangement of the keyboard, even if it is less efficient.

(E) Computer keyboards include many keys that were not needed on manual or electric typewriters.