Which of the following most logically completes the argument?

Although the pesticide TDX has been widely used by fruit growers since the early
1960’s, a regulation in force since 1960 has prohibited sale of fruit on which any TDX
residue can be detected. That regulation is about to be replaced by one that allows sale of fruit on which trace amounts of TDX residue are detected. In fact, however, the change will not allow more TDX on fruit than was allowed in the 1960’s, because ______.

A. pre-1970 techniques for detecting TDX residue could detect it only when it was
present on fruit in more than the trace amounts allowed by the new regulations

B. many more people today than in the 1960’s habitually purchase and eat fruit
without making an effort to clean residues off the fruit

C. people today do not individually consume any more pieces of fruit, on average,
than did the people in the 1960’s

D. at least a small fraction of the fruit sold each year since the early 1960’s has had
on it greater levels of TDX than the regulation allows

E. the presence of TDX on fruit in greater than trace amounts has not been shown to
cause any harm even to children who eat large amounts of fruit

Stuck between A and D here....Please explain....

Regards,
Phil

To me the answer is A for the following reason:

The argument says that even though the pesticide law has become more lenient (from no TDX to traces of TDX being allowed) the amount of TDX on fruits will be the same as was allowed in the 60s. You have to explain how this will be the case?

The problem is that you are starting with the assumption that there was No TDX residue in the 60s but now that the law has become lenient why shouldn't there be any residue? But just think what if there actually was TDX residue (as per option 1) on fruits in the 60s but could not be detected by the authorities?

The authorities would have thought there was no residue while there actually was some residue and according to Option A this residue is the same (in terms of quantity) as the traces that have been allowed by the change to the Regulation now.

Hence its perfectly possible that, even though the Regulation has become more lenient, the actual amount of TDX present on fruits remains the same.

I fail to see how option D is relevant because even if some fruits have been always sold with higher levels of TDX than is allowed, it's probably only because these have escaped detection but you can't assume that this will be the case all the time. Also if the fruit is escaping detection then the amount of TDX on the fruit becomes irrelevant as you could have as much TDX on these fruits as you want. So why no more TDX than was allowed in the 60s?

Hope this helps.

Cheers!

nice explanation of the correct answer (it's A).

--

the reason why choice (d) is incorrect is because it is completely irrelevant to the argument.
the argument is only concerned with what is allowed or not allowed by the regulation -- i.e., with the particulars and enforceability of the rule itself.
the presence or absence of actual violations of the rule has nothing to do with this argument.

as an analogy, if i'm arguing something like "the sentences for drug possession in this state are too strict", my argument does not change depending on whether there are people who have actually been subjected to those sentences.

hi RoN there is one redundancy error in ur reply??????
the reason why choice (d) is incorrect is because it is completely irrelevant to the argument
am right sir?

that is technically redundant, yes. (if you saw it on a SC problem, you could eliminate the choice(s) containing it.)

I can choose the right answer. But i still have some problem with A. I think it is quite possible that after 1970,techniques might improve and people can detect the TDX more precisely, then the answer choice A will not logically complete this sentence .
Plz correct me if i am wrong.
Thanks a lot

2 things very wrong here.

1/ you can't just make up some scenario (even if that scenario is “very reasonable”) and then build an argument on something that you made up at random!
a good rule of thumb here: if your line of reasoning includes the word "might", then STOP. you can't build an argument on "this might happen".

2/ if the techniques for detecting tdx on fruit improve even more, that will actually make the argument even stronger -- i.e., you have somehow gotten the reasoning exactly backwards.
the point of the argument is that the allowed amounts of tdx today will be either the same as or less than the amounts allowed in the 1960's. if you assume the hypothetical above (which you are not allowed to do anyway), then that becomes more likely to be true.