Physician: The patient is suffering either from disease X or else from disease Y, but there is no available test for distinguishing X from Y. Therefore, since there is an effective treatment for Y but no treatment for X, the patient has a case of Y.
What this question is testing
Reasoning
The physician faces a choice: it is X or Y, no test can tell, treatment exists only for Y. If it is X, nothing works — game over. If it is Y, treatment works. So the only scenario where any action helps the patient is the Y scenario. The physician proceeds on that assumption.
Evaluate
This is a classic move. Imagine you are stuck in a remote area and you might or might not have cell service. You cannot test it without trying. If you have service, calling for help works. If you do not, nothing you do with the phone matters. So you act as if you have service — because it is your only path to a good outcome.
Goal
Find the principle that captures this: when success depends on an uncontrollable circumstance being favorable, act as if it is favorable.
Reading along? Open the full official question in LawHub — we show a fragment here and keep the reasoning in our own words.