raghavs wrote:
As a practical matter, the copper available for industrial use should not be thought of as limited by the quantity of copper deposits, known or unknown. The transmutation of one chemical element into another is a modern reality, through the methods of nuclear physics. Therefore, the quantity of a natural resource such as copper cannot be calculated even in principle, because copper can be made from other metals.
Which of the following, if true, is the strongest argument against the argument above?
A) Although it is possible that additional deposits of copper will be found, geological considerations strongly indicate that they will not amount to more than fifty-year supply.
B) The production of copper from other metals in industrial quantities would be prohibitively expensive in energy and materials.
C) Synthetic materials have been discovered that can serve as practical substitutes for copper in most of its uses.
D) It will be impractical, in the foreseeable future, to mine any deposits of metal that may exist on the moon or on other planets.
E) Methods for estimating the amount of copper available in currently known deposits have become very sophisticated and have proved some accurate
IMO B is the correct answer though I went for E.
Conclusion says "the quantity of a natural resource
such as copper cannot be calculated even in principle, because copper can be made from other metals.
It implies that copper is one material and there are many other materials from which it can be extracted and it may be an endless list. So, if that is the case, it would be almost impossible to calculate the actual quantity of copper as to extract copper from all other materials would be prohibitively expensive.
As for option E, word "proved some accurate" is the problem as it may imply that methods used for estimating are good but only some of them are accurate. Because of this we can estimate some copper quantity accurately but not all.