(B) discusses evaluating the reliability of numerical comparisons of the accuracy of translations. This refers specifically to the part of the passage that states computer translation programs have "an 80 percent accuracy rate." This statistic plays a significant role in supporting the passage's conclusion that "it is better to use a computer translation program than human translators" to quickly translate a long document. If this number could not be reasonably obtained, it would notably undermine the strength of the argument. This is because, if it is impossible for the figure to be reasonably deduced, we could not reliably trust the statistic. For example, if we could not be sure that the figure was 80% instead of a lower figure (say 50% for example), we could not logically come to the passage's conclusion. Therefore, evaluating the reliability of numerical comparisons of the accuracy of translations is relatively important to evaluating the overall argument.
Also, it is important to remember that the question asks us to choose the answer that presents the issue that is "LEAST important to resolve in evaluating the argument." So, as long as (C) is less helpful than (B) is, (B) would be incorrect.
Does that make sense? Please let us know if you have any other questions and best of luck with your studies!
