Bernand: For which language, and thus which frequency distribution of letters and letter sequences, was the standard typewriter keyboard designed?
Cora: To ask this question, you must be making a mistaken assumption: that typing speed was to be maximized. The real danger with early typewriters was that operators would hit successive keys too quickly, thereby crashing typebars into each other, bending connecting wires and so on. So the idea was to slow the operator down by making the most common letter sequences awkward to type.
Bernand: This is surely not right! These technological limitations have long since vanished, yet the keyboard is still as it was then.
Which one of the following, if true, could be used by Cora to counter Bernard’s rejection of her explanation?
(A) Typewriters and word-processing equipment are typically sold to people who have learned to use the standard keyboard and who, therefore, demand it in equipment they buy.
(B) Typewriters have been superseded in most offices by word-processing equipment, which has inherited the standard keyboard from typewriters.
(C) The standard keyboard allows skilled operators to achiever considerable typing speeds, thought it makes acquiring such skills relatively difficult.
(D) A person who has learned one keyboard layout can readily learn to use a second one in place of the first, but only with difficulty learn to use a second one alongside the first.
(E) It is now possible to construct typewriter and word-processing equipment in which a single keyboard can accommodate two or even more different keyboard layouts, each accessible to the operator at will.

I think it's A.

Good point! I instictively picked A. I see that B could also be argued. But B speaks "only" about offices where typewrites have been replaced by word processing equipements with similar keyboard.
We don't know if "all or most" the users of typewriters have switched to new word processing equipment.

A includes both typewrites and word processing equipment and also mentions most buyers (typically sold to people) demand the new equipment.

Again I love one of "rhyme's" quotes : The longer the story that you need to tell, worse the answer is. B, IMHO, needs a longer story to be told.. Hence not the best choice.

BTW (I think) the correct idiom is:
Agree to an idea/proposal
OR Agree with a person/explanation
_________________

"To dream anything that you want to dream, that is the beauty of the human mind. To do anything that you want to do, that is the strength of the human will. To trust yourself, to test your limits, that is the courage to succeed."

- Bernard Edmonds

I will go with A as it the only one to counter the argument 'These technological limitations have long since vanished, yet the keyboard is still as it was then.,

Will go with A.

Bernard argues that what stated by Cora is correct then even after technological innovations why the old keyboard layout is used.

To counter this argument, Cora can argue that since people who use the new technology learned to type with old layout they feel it more comfortable.