Both Writewell and Express provide round-the-clock telephone assistance to any customer who uses their word-processing software. Since customers only call the hot lines when they find the software difficult to use, and the Writewell hot line receives four times as many calls as the Express hot line, Writewell’s word-processing software must be more difficult to use than Express’s.

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


(A) Calls to the Express hot line are almost twice as long, on average, as are calls to the Writewell hot line.

(B) Express has three times the number word-processing software customers that Writewell has.

(C) Express receives twice as many letters of complaint about its word-processing software as Writewell receives about its word-processing software.

(D) The number of calls received by each of the two hot lines has been gradually increasing.

(E) The Writewell hot-line number is more widely publicized that the Express hot-line number.

Shubhasish Just a tiny bit of advice.

Sharing your reasoning along with the answers will help you and others gain clarity.
There's no point posting just the answer. A lot of people have answers with them, its the correct way of analysis of the argument and the answer choices that everyone seeks to improve.

Also, system might automatically delete your post[the system is designed to to seek and delete short posts such as these and hence to facilitate discussions]

Must be (B), if even after having three times the number word-processing software customers that Writewell is receiving four times as many calls as the Express hot line, then it clearly indicates that Writewell’s word-processing software must be more difficult to use than Express’s.
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Yes and why do they prefer ? it's easy and not difficult and this thinking helps us in clarifying that B indeed is a strengthener