Hi All,
I typically use the standard 3 step approach suggested by
egmat :
Meaning analysis:A substance derived from the Madagascar periwinkle, which has proved useful in decreasing mortality among young leukemia patients, is cultivated in China as part of a program to integrate traditional herbal medicine into a contemporary system of health care.
Imagine that the wheat plant is cultivated and the flour is useful for a treatment. Now flour is a derivative of the plant, can the flour be cultivated ?
Now based on this analogy lets understand the original question:
What is useful in decreasing mortality ?
The derivative
What is cultivated ?
Madagascar Periwinkle.
Error Analysis:1. "from the madagascar periwinkle, which has proved useful" --> "Which" always refer to the immediate preceding noun which in this case is the periwinkle. As per our meaning analysis "the derivative" is what is useful
2. " A substance derived from the Madagascar periwinkle,
which has proved useful in decreasing mortality among young leukemia patients, is cultivated " --> The striked out portion is providing more information about periwinkle and should be ignored to understand what is cultivated.
A substance derived, ..., is cultivated --> This is incorrect as per our analysis
Answers analysis:(A) A substance derived from the Madagascar periwinkle, which has proved useful in decreasing mortality among young leukemia patients,-->
As pointed out in the error analysis
(B) A derivative, which has proved useful in decreasing mortality among young leukemia patients, of the Madagascar periwinkle, -->
A Derivative,..., is cultivated --> Incorrect as pointed in the error analysis.(C) A Madagascar periwinkle derivative, which has proved useful in decreasing mortality among young leukemia patients,-->
Derivative is cultivated--> As pointed in the error analysis, this distorts the meaning(D) The Madagascar periwinkle has a derivative which has proved useful in decreasing mortality among young leukemia patients, that -->
"that" has a hanging precedent noun. In this statement "that" can refer to patients(E) The Madagascar periwinkle, a derivative of which has proved useful in decreasing mortality among young leukemia patients, -->
This correctly addresses the mistakes.
I hope this is helpful !
Regards,
Shradha