Ravi: The highest priority should be given to the needs of

Ravi:
The highest priority should be given to the needs of the sales department, because without successful sales the company as a whole would fail.
Ed:
There are several departments other than sales that must also function successfully for the company to succeed. It is impossible to give the highest priority to all of them

Ed criticizes Ravi's argument by pointing out:

A) That the sales department taken by itself is not critical to the company's success as a whole.
B) The ambiguity of the term "Highest Priority"
C) That the department other than sales are more vital to the company's success.
D) An absurd consequence of its apparent assumption that a department's necessity earns it the highest priority
E) That Ravi makes a generalization from an atypical case.

This one is from Challenging Sets.

Request you to clear the following doubts

1- I narrowed down to A and D and then finally chose A, however it is incorrect. Can we negate the option A on the basis that option A is focusing on Subject Matter not on Argumentative Technique

2- I adopted the similar strategy to the question posted here-
mr-janeck-i-don-t-believe-stevenson-will-win-the-election-90932.html

However, answer turned out to be incorrect. I asked myself what question could have Ravi posted for which Ed providing an answer.
So, the answer turned out to be. i.e Ravi could have posted this question -
Sales department must function successfully for the company to succeed. Hence, it should be given highest priority.
This is what the answer A speaks.

Please let me know where I am going wrong.