When using a manufactured pattern to make clothing, a tailor alters the pattern to accommodate any future distortion of the fabric. Also, unless the clothing is to be worn by a person whose measurements precisely match the pattern size, the tailor alters the pattern to fit the wearer exactly. Thus, a professional tailor never blindly follows a pattern, but always adjusts the pattern to fit the wearer exactly.
The conclusion of the argument is the following:
a professional tailor never blindly follows a pattern, but always adjusts the pattern to fit the wearer exactly
The support for the conclusion appears to be the following, though we could argue that the first statement of the passage doesn't really have to do with the conclusion:
When using a manufactured pattern to make clothing, a tailor alters the pattern to accommodate any future distortion of the fabric.
and
unless the clothing is to be worn by a person whose measurements precisely match the pattern size, the tailor alters the pattern to fit the wearer exactly
We see that the reasoning of the argument jumps from the fact that a tailor alters a pattern "unless the clothing is to be worn by a person whose measurements precisely match the pattern size" to the conclusion that a professional tailor "always" adjusts a pattern.
One aspect of the argument could jump out at us is that doing something "unless" something is the case is not "always" doing it. In other words, it could be that, sometimes, "the clothing IS to be worn by a person whose measurements precisely match the pattern," in which case a tailor would NOT alter the pattern.
So, basically, the premise is about something that sometimes happens whereas the conclusion is about something that "always" happens.
The conclusion follows logically if which one of the following is assumed?
This is an Assumption question, and the correct answer will render the argument effective by connecting the premise about what sometimes happens with the conclusion about what always happens.
(A) Most manufactured patterns do not already accommodate the future distortion of fabrics that shrink or stretch.
The conclusion is basically that a professional tailor always adjusts a pattern to "fit the wearer exactly."
It's not that a tailor always adjusts a pattern to exactly accommodate any future distortion of the fabric.
So, even if this choice is not true and most manufactured patterns DO already accommodate the future distortion of fabrics that shrink or stretch, the conclusion could still follow logically from the evidence. After all, even if a tailor does not have to adjust a pattern to accommodate future distortions, the tailor could still adjust the pattern to fit the wearer.
Eliminate.
(B) At least some tailors who adjust patterns to the wearer and to the fabrics used are professional tailors.
This choice doesn't state an assumption because the premise is a general statement about "the tailor." In other words, the statement "the tailor alters the pattern to fit the wearer exactly," applies to ALL tailors.
So, the argument does not assume that professional tailors adjust patterns. Rather, it basically states directly that all tailors, including professional tailors, adjust patterns.
Eliminate.
(C) The best tailors are those most able to alter patterns to fit the wearer exactly.
The conclusion of the argument is not about "the best tailors."
So, the argument does not involve any assumptions about "the best tailors."
Eliminate.
(D) All professional tailors sew only for people whose measurements do not exactly match their chosen patterns.
Above, we saw that the premise is basically that tailors always adjust patterns to fit wearers "unless the clothing is to be worn by a person whose measurements precisely match the pattern size," meaning that, sometimes, tailors may not adjust patterns to fit wearers.
Then, the conclusion is that "a professional tailor never blindly follows a pattern, but always adjusts the pattern to fit the wearer exactly."
So, the argument jumps from evidence about something that SOMETIMES happens to a conclusion about something that ALWAYS happens.
In other words, the argument assumes that a fact about something that sometimes happens supports a conclusion about something that always happens.
Therefore, this choice is interesting because, by saying that all professional tailors sew only for people whose measurements do not match patterns, it eliminates the SOMETIMES aspect of the evidence by indicating that professional tailors NEVER work in situations such that "the clothing is to be worn by a person whose measurements precisely match the pattern size."
If professional tailors never work in such situations, then they work only in situations such that people's measurements do NOT match patterns.
In that case, the fact that "unless the clothing is to be worn by a person whose measurements precisely match the pattern size, the tailor alters the pattern to fit the wearer exactly," logically supports the conclusion "a professional tailor never blindly follows a pattern, but always adjusts the pattern to fit the wearer exactly," because in that case, the exceptions in which "the clothing is to be worn by a person whose measurements precisely match the pattern" have been eliminated.
So, when this choice is added to the argument, the evidence effectively supports the conclusion because we have basically the following logic:
Premise: A tailor always adjust a patterns to fit the wearer except in certain situations.
Assumption (this choice): Professional tailors never work in such situations.
Conclusion: Therefore, professional tailors always adjust patterns to fit wearers.
Keep.
(E) A professional tailor can always estimate exactly how much a fabric will shrink or stretch.
The conclusion is basically that a professional tailor always adjusts a pattern to "fit the wearer exactly."
It's not that a tailor adjusts a pattern to exactly accommodate any future distortion of the fabric.
So, the argument does not assume that "A professional tailor can always estimate exactly how much a fabric will shrink or stretch," because a tailor does not have to estimate that to adjust a pattern to fit the wearer.
Eliminate.
Correct answer: D