Economist:
Global recessions can never be prevented, for they could be prevented only if they were predictable. Yet economists, using the best techniques at their disposal, consistently fail to accurately predict global recessions.
The economist's argument is most vulnerable to the criticism that:
(A) Presupposed in a premise the conclusion that it purports to establish
(B) Fails to establish that
economists claim to be able to accurately predict global recessions - WRONG. Altogether goes against premise.
(C) Treats the predictability of an event, which is required for the event to be
preventable, as a characteristic that assures its prevention - WRONG. Predictable and preventable are different.
(D) Fails to address the possibility that the techniques available to economists for the predicting of global recessions will significantly improve
(E)
Implicitly bases an inference that something will not occur solely on the information that its occurrence is not predictable - WORNG. Like B, this is going against premise.
The highlighted test established that in the past global recession has not been predicted, thus prevented. So, in future as well things would not change. The problem lies here itself. Till this point things were okay.
Although I could identify conclusion(highlighted text), I fell for 2nd best option - A. Only if one realises that future may bring improvements, D looks good. Otherwise, if past only considered A looks good IMO. Not sure how D could be an answer.