A new test for AIDS has proved helpful
in eliminating blood, contaminated with the virus, from the nation's blood supply.Option Elimination - What is the difference between "help in ING" and "help to"
"Help in" is used when we want to say that the assistance contributes to achieving a specific goal. E.g., The new software will help in improving productivity. Here, "the new software" contributes to achieving a specific goal: improving productivity.
"Help to" is used when we say that the assistance enables someone to perform a specific task. E.g., The tutor helps to develop student's problem-solving skills. Here, the assistance provided by the teacher enables the students to develop problem-solving skills)
Here, are we achieving something with the new test, or the new test is enabling someone to perform the task? Here, we are achieving a goal, and what is that goal, "eliminating blood that is contaminated with the virus."
But Idiom should be the last resort to eliminate the option. And we have enough issues in the wrong answers to eliminate them even if we don't know this distinction.
(A) in eliminating blood, contaminated with the virus, from the nation's blood supply - if we remove the non-essential modifier from the sentence, it reads like "eliminating blood from the nation's blood supply." Are we trying to eliminate all the blood? Thats nonsense. Wrong.
(B) in eliminating blood from the nation's blood supply that is contaminated with the virus - "that" modifies "blood supply." Are we saying that we are eliminating the blood supply? No. Wrong.
(C) in eliminating from the nation's blood supply blood that is contaminated with the virus - "that" correctly modifies blood. The modifier "from the nation's blood supply" is placed correctly after elimination. Though, in general readability, this is a poor way of saying. Nonetheless, grammatically and meaning-wise, it's ok.
(D) to eliminate blood that is contaminated with the virus from the nation's blood supply - the modifier "from the nation's blood supply" modifies "the virus" as if the virus is from the blood supply. Wrong.
(E) to eliminate blood from the nation's blood supply that is contaminated with the virus - "that" referring to "blood supply" creates the wrong meaning.
We can eliminate options just because of another issue, but if we know the distinction between "help in" and "help to," it's a plus.